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Thursday, November 14, 2019

Creation–evolution controversy

From Wikipedia, the free encyclopedia
 
A satirical cartoon from 1882, parodying Charles Darwin's theory of evolution, on the publication of The Formation of Vegetable Mould through the Action of Worms (1881)
 
The creation–evolution controversy (also termed the creation vs. evolution debate or the origins debate) involves an ongoing, recurring cultural, political, and theological dispute about the origins of the Earth, of humanity, and of other life. Species were once widely believed to be fixed products of divine creation in accordance with creationism, but since the mid-19th century evolution by natural selection has been established as an empirical scientific fact. 

The debate is religious, not scientific: in the scientific community, evolution is accepted as fact and efforts to sustain the traditional view are almost universally regarded as pseudoscience. While the controversy has a long history, today it has retreated to be mainly over what constitutes good science education, with the politics of creationism primarily focusing on the teaching of creationism in public education. Among majority-Christian countries, the debate is most prominent in the United States, where it may be portrayed as part of a culture war. Parallel controversies also exist in some other religious communities, such as the more fundamentalist branches of Judaism and Islam. In Europe and elsewhere, creationism is less widespread (notably, the Catholic Church and Anglican Communion both accept evolution), and there is much less pressure to teach it as fact.

Christian fundamentalists repudiate the evidence of common descent of humans and other animals as demonstrated in modern paleontology, genetics, histology and cladistics and those other sub-disciplines which are based upon the conclusions of modern evolutionary biology, geology, cosmology, and other related fields. They argue for the Abrahamic accounts of creation, and, in order to attempt to gain a place alongside evolutionary biology in the science classroom, have developed a rhetorical framework of "creation science". In the landmark Kitzmiller v. Dover, the purported basis of scientific creationism was exposed as a wholly religious construct without formal scientific merit.

The Catholic Church now recognizes the existence of evolution. Pope Francis has stated: "God is not a demiurge or a magician, but the Creator who brought everything to life...Evolution in nature is not inconsistent with the notion of creation, because evolution requires the creation of beings that evolve." The rules of genetic evolutionary inheritance were first discovered by a Catholic priest, the Augustinian monk Gregor Mendel, who is known today as the founder of modern genetics

According to a 2014 Gallup survey, "More than four in 10 Americans continue to believe that God created humans in their present form 10,000 years ago, a view that has changed little over the past three decades. Half of Americans believe humans evolved, with the majority of these saying God guided the evolutionary process. However, the percentage who say God was not involved is rising." A 2015 Pew Research Center survey found "that while 37% of those older than 65 thought that God created humans in their present form within the last 10,000 years, only 21% of respondents between the ages of 18 and 29 agreed."

The debate is sometimes portrayed as being between science and religion, and the United States National Academy of Sciences states:
Today, many religious denominations accept that biological evolution has produced the diversity of living things over billions of years of Earth's history. Many have issued statements observing that evolution and the tenets of their faiths are compatible. Scientists and theologians have written eloquently about their awe and wonder at the history of the universe and of life on this planet, explaining that they see no conflict between their faith in God and the evidence for evolution. Religious denominations that do not accept the occurrence of evolution tend to be those that believe in strictly literal interpretations of religious texts.
— National Academy of Sciences, Science, Evolution, and Creationism

History

The creation–evolution controversy began in Europe and North America in the late 18th century, when new interpretations of geological evidence led to various theories of an ancient Earth, and findings of extinctions demonstrated in the fossil geological sequence prompted early ideas of evolution, notably Lamarckism. In England these ideas of continuing change were at first seen as a threat to the existing "fixed" social order, and both church and state sought to repress them. Conditions gradually eased, and in 1844 Robert Chambers's controversial Vestiges of the Natural History of Creation popularized the idea of gradual transmutation of species. The scientific establishment at first dismissed it scornfully and the Church of England reacted with fury, but many Unitarians, Quakers and Baptists—groups opposed to the privileges of the established church—favoured its ideas of God acting through such natural laws.

Contemporary reaction to Darwin

A satirical image of Darwin as an ape from 1871 reflects part of the social controversy over the fact that humans and apes share a common lineage.
 
Asa Gray around the time he published Darwiniana.
By the end of the 19th century, there was no serious scientific opposition to the basic evolutionary tenets of descent with modification and the common ancestry of all forms of life.
— Thomas Dixon, Science and Religion: A Very Short Introduction
The publication of Darwin's On the Origin of Species in 1859 brought scientific credibility to evolution, and made it a respectable field of study.

Despite the intense interest in the religious implications of Darwin's book, theological controversy over higher criticism set out in Essays and Reviews (1860) largely diverted the Church of England's attention. Some of the liberal Christian authors of that work expressed support for Darwin, as did many Nonconformists. The Reverend Charles Kingsley, for instance, openly supported the idea of God working through evolution. Other Christians opposed the idea, and even some of Darwin's close friends and supporters—including Charles Lyell and Asa Gray—initially expressed reservations about some of his ideas. Gray later became a staunch supporter of Darwin in America, and collected together a number of his own writings to produce an influential book, Darwiniana (1876). These essays argued for a conciliation between Darwinian evolution and the tenets of theism, at a time when many on both sides perceived the two as mutually exclusive. Gray said that investigation of physical causes was not opposed to the theological view and the study of the harmonies between mind and Nature, and thought it "most presumable that an intellectual conception realized in Nature would be realized through natural agencies." Thomas Huxley, who strongly promoted Darwin's ideas while campaigning to end the dominance of science by the clergy, coined the term agnostic to describe his position that God's existence is unknowable. Darwin also took this position, but prominent atheists including Edward Aveling and Ludwig Büchner also took up evolution and it was criticized, in the words of one reviewer, as "tantamount to atheism." Following the lead of figures such as St. George Jackson Mivart and John Augustine Zahm, Roman Catholics in the United States became accepting of evolution itself while ambivalent towards natural selection and stressing humanity's divinely imbued soul. The Catholic Church never condemned evolution, and initially the more conservative-leaning Catholic leadership in Rome held back, but gradually adopted a similar position.

During the late 19th century evolutionary ideas were most strongly disputed by the premillennialists, who held to a prophecy of the imminent return of Christ based on a form of Biblical literalism, and were convinced that the Bible would be invalidated if any error in the Scriptures was conceded. However, hardly any of the critics of evolution at that time were as concerned about geology, freely granting scientists any time they needed before the Edenic creation to account for scientific observations, such as fossils and geological findings. In the immediate post-Darwinian era, few scientists or clerics rejected the antiquity of the earth or the progressive nature of the fossil record. Likewise, few attached geological significance to the Biblical flood, unlike subsequent creationists. Evolutionary skeptics, creationist leaders and skeptical scientists were usually either willing to adopt a figurative reading of the first chapter of the Book of Genesis, or allowed that the six days of creation were not necessarily 24-hour days.

Science professors at liberal northeastern universities almost immediately embraced the theory of evolution and introduced it to their students. However, some people in parts of the south and west of the United States, which had been influenced by the preachings of Christian fundamentalist evangelicals, rejected the theory as immoral.

In the United Kingdom, Evangelical creationists were in a tiny minority. The Victoria Institute was formed in 1865 in response to Essays and Reviews and Darwin's On the Origin of Species. It was not officially opposed to evolution theory, but its main founder James Reddie objected to Darwin's work as "inharmonious" and "utterly incredible", and Philip Henry Gosse, author of Omphalos, was a vice-president. The institute's membership increased to 1897, then declined sharply. In the 1920s George McCready Price attended and made several presentations of his creationist views, which found little support among the members. In 1927 John Ambrose Fleming was made president; while he insisted on creation of the soul, his acceptance of divinely guided development and of Pre-Adamite humanity meant he was thought of as a theistic evolutionist.

Creationism in theology

At the beginning of the 19th century debate had started to develop over applying historical methods to Biblical criticism, suggesting a less literal account of the Bible. Simultaneously, the developing science of geology indicated the Earth was ancient, and religious thinkers sought to accommodate this by day-age creationism or gap creationism. Neptunianist catastrophism, which had in the 17th and 18th centuries proposed that a universal flood could explain all geological features, gave way to ideas of geological gradualism (introduced in 1795 by James Hutton) based upon the erosion and depositional cycle over millions of years, which gave a better explanation of the sedimentary column. Biology and the discovery of extinction (first described in the 1750s and put on a firm footing by Georges Cuvier in 1796) challenged ideas of a fixed immutable Aristotelian "great chain of being." Natural theology had earlier expected that scientific findings based on empirical evidence would help religious understanding. Emerging differences led some to increasingly regard science and theology as concerned with different, non-competitive domains.

When most scientists came to accept evolution (by around 1875), European theologians generally came to accept evolution as an instrument of God. For instance, Pope Leo XIII (in office 1878–1903) referred to longstanding Christian thought that scriptural interpretations could be reevaluated in the light of new knowledge, and Roman Catholics came around to acceptance of human evolution subject to direct creation of the soul. In the United States the development of the racist Social Darwinian eugenics movement by certain circles led a number of Catholics to reject evolution. In this enterprise they received little aid from conservative Christians in Great Britain and Europe. In Britain this has been attributed to their minority status leading to a more tolerant, less militant theological tradition. This continues to the present. In his speech at the Pontifical Academy of Sciences in 2014, Pope Francis declared that he accepted the Big Bang theory and the theory of evolution and that God was not "a magician with a magic wand".

Development of creationism in the United States

A Fundamentalist cartoon portraying Modernism as the descent from Christianity to atheism, first published in 1922.
 
At first in the U.S., evangelical Christians paid little attention to the developments in geology and biology, being more concerned with the rise of European higher Biblical criticism which questioned the belief in the Bible as literal truth. Those criticizing these approaches took the name "fundamentalist"—originally coined by its supporters to describe a specific package of theological beliefs that developed into a movement within the Protestant community of the United States in the early part of the 20th century, and which had its roots in the Fundamentalist–Modernist Controversy of the 1920s and 1930s. The term in a religious context generally indicates unwavering attachment to a set of irreducible beliefs.

Up until the early mid-20th century, mainline Christian denominations within the United States showed little official resistance to evolution. Around the start of the 20th century some evangelical scholars had ideas accommodating evolution, such as B. B. Warfield who saw it as a natural law expressing God's will. By then most U.S. high-school and college biology classes taught scientific evolution, but several factors, including the rise of Christian fundamentalism and social factors of changes and insecurity in more traditionalist Bible Belt communities, led to a backlash. The numbers of children receiving secondary education increased rapidly, and parents who had fundamentalist tendencies or who opposed social ideas of what was called "survival of the fittest" had real concerns about what their children were learning about evolution.

British creationism

The main British creationist movement in this period, the Evolution Protest Movement (EPM), formed in the 1930s out of the Victoria Institute, or Philosophical Society of Great Britain (founded in 1865 in response to the publication of Darwin's On the Origin of Species in 1859 and of Essays and Reviews in 1860). The Victoria Institute had the stated objective of defending "the great truths revealed in Holy Scripture ... against the opposition of Science falsely so called".[citation needed] Although it did not officially oppose evolution, it attracted a number of scientists skeptical of Darwinism, including John William Dawson and Arnold Guyot. It reached a high point of 1,246 members in 1897, but quickly plummeted to less than one third of that figure in the first two decades of the twentieth century. Although it opposed evolution at first, the institute joined the theistic evolution camp by the 1920s, which led to the development of the Evolution Protest Movement in reaction. Amateur ornithologist Douglas Dewar, the main driving-force within the EPM, published a booklet entitled Man: A Special Creation (1936) and engaged in public speaking and debates with supporters of evolution. In the late 1930s he resisted American creationists' call for acceptance of flood geology, which later led to conflict within the organization. Despite trying to win the public endorsement of C. S. Lewis (1898–1963), the most prominent Christian apologist of his day, by the mid-1950s the EPM came under control of schoolmaster/pastor Albert G. Tilney, whose dogmatic and authoritarian style ran the organization "as a one-man band", rejecting flood geology, unwaveringly promoting gap creationism, and reducing the membership to lethargic inactivity. It was renamed the Creation Science Movement (CSM) in 1980, under the chairmanship of David Rosevear, who holds a Ph.D. in organometallic chemistry from the University of Bristol. By the mid-1980s the CSM had formally incorporated flood geology into its "Deed of Trust" (which all officers had to sign) and condemned gap creationism and day-age creationism as unscriptural.

United States legal challenges and their consequences

In 1925 Tennessee passed a statute, the Butler Act, which prohibited the teaching of the theory of evolution in all schools in the state. Later that year Mississippi passed a similar law, as did Arkansas in 1927. In 1968 the Supreme Court of the United States struck down these "anti-monkey" laws as unconstitutional, "because they established a religious doctrine violating both the First and Fourth Amendments to the United States Constitution."

In more recent times religious fundamentalists who accept creationism have struggled to get their rejection of evolution accepted as legitimate science within education institutions in the U.S. A series of important court cases has resulted.

Butler Act and the Scopes monkey trial (1925)

Anti-Evolution League at the Scopes Trial
 
After 1918, in the aftermath of World War I, the Fundamentalist–Modernist controversy had brought a surge of opposition to the idea of evolution, and following the campaigning of William Jennings Bryan several states introduced legislation prohibiting the teaching of evolution. By 1925, such legislation was being considered in 15 states, and had passed in some states, such as Tennessee. The American Civil Liberties Union offered to defend anyone who wanted to bring a test case against one of these laws. John T. Scopes accepted, and confessed to teaching his Tennessee class evolution in defiance of the Butler Act, using the textbook by George William Hunter: A Civic Biology: Presented in Problems (1914). The trial, widely publicized by H. L. Mencken among others, is commonly referred to as the Scopes Monkey Trial. The court convicted Scopes, but the widespread publicity galvanized proponents of evolution. Following an appeal of the case to the Tennessee Supreme Court, the Court overturned the decision on a technicality (the judge had assessed the minimum $100 fine instead of allowing the jury to assess the fine).

Although it overturned the conviction, the Court decided that the Butler Act was not in violation of the Religious Preference provisions of the Tennessee Constitution (Section 3 of Article 1), which stated "that no preference shall ever be given, by law, to any religious establishment or mode of worship". The Court, applying that state constitutional language, held:
We are not able to see how the prohibition of teaching the theory that man has descended from a lower order of animals gives preference to any religious establishment or mode of worship. So far as we know, there is no religious establishment or organized body that has in its creed or confession of faith any article denying or affirming such a theory.... Protestants, Catholics, and Jews are divided among themselves in their beliefs, and that there is no unanimity among the members of any religious establishment as to this subject. Belief or unbelief in the theory of evolution is no more a characteristic of any religious establishment or mode of worship than is belief or unbelief in the wisdom of the prohibition laws. It would appear that members of the same churches quite generally disagree as to these things.
... Furthermore, [the Butler Act] requires the teaching of nothing. It only forbids the teaching of evolution of man from a lower order of animals.... As the law thus stands, while the theory of evolution of man may not be taught in the schools of the State, nothing contrary to that theory [such as Creationism] is required to be taught.
... It is not necessary now to determine the exact scope of the Religious Preference clause of the Constitution ... Section 3 of Article 1 is binding alike on the Legislature and the school authorities. So far we are clear that the Legislature has not crossed these constitutional limitations.
— Scopes v. State, 289 S.W. 363, 367 (Tenn. 1927).
The interpretation of the Establishment Clause of the United States Constitution up to that time held that the government could not establish a particular religion as the State religion. The Tennessee Supreme Court's decision held in effect that the Butler Act was constitutional under the state Constitution's Religious Preference Clause, because the Act did not establish one religion as the "State religion". As a result of the holding, the teaching of evolution remained illegal in Tennessee, and continued campaigning succeeded in removing evolution from school textbooks throughout the United States.

Epperson v. Arkansas (1968)

In 1968 the United States Supreme Court invalidated a forty-year-old Arkansas statute that prohibited the teaching of evolution in the public schools. A Little Rock, Arkansas, high-school-biology teacher, Susan Epperson, filed suit, charging that the law violated the federal constitutional prohibition against establishment of religion as set forth in the Establishment Clause. The Little Rock Ministerial Association supported Epperson's challenge, declaring, "to use the Bible to support an irrational and an archaic concept of static and undeveloping creation is not only to misunderstand the meaning of the Book of Genesis, but to do God and religion a disservice by making both enemies of scientific advancement and academic freedom". The Court held that the United States Constitution prohibits a state from requiring, in the words of the majority opinion, "that teaching and learning must be tailored to the principles or prohibitions of any religious sect or dogma". But the Supreme Court decision also suggested that creationism could be taught in addition to evolution.

Daniel v. Waters (1975)

Daniel v. Waters was a 1975 legal case in which the United States Court of Appeals for the Sixth Circuit struck down Tennessee's law regarding the teaching of "equal time" of evolution and creationism in public-school science classes because it violated the Establishment Clause. Following this ruling, creationism was stripped of overt biblical references and rebranded "Creation Science", and several states passed legislative acts requiring that this be given equal time with the teaching of evolution.

Creation science

Detail of Noah's Ark, oil painting by Edvard Hicks (1846)
 
As biologists grew more and more confident in evolution as the central defining principle of biology, American membership in churches favoring increasingly literal interpretations of scripture also rose, with the Southern Baptist Convention and Lutheran Church–Missouri Synod outpacing all other denominations. With growth and increased finances, these churches became better equipped to promulgate a creationist message, with their own colleges, schools, publishing houses, and broadcast media.

In 1961 Presbyterian and Reformed Publishing released the first major modern creationist book: John C. Whitcomb and Henry M. Morris' influential The Genesis Flood: The Biblical Record and Its Scientific Implications. The authors argued that creation was literally 6 days long, that humans lived concurrently with dinosaurs, and that God created each "kind" of life individually. On the strength of this, Morris became a popular speaker, spreading anti-evolutionary ideas at fundamentalist churches, colleges, and conferences. Morris' Creation Science Research Center (CSRC) rushed publication of biology textbooks that promoted creationism. Ultimately, the CSRC broke up over a divide between sensationalism and a more intellectual approach, and Morris founded the Institute for Creation Research, which was promised to be controlled and operated by scientists. During this time, Morris and others who supported flood geology adopted the terms "scientific creationism" and "creation science". The "flood geology" theory effectively co-opted "the generic creationist label for their hyperliteralist views."

Court cases

McLean v. Arkansas
In 1982, another case in Arkansas ruled that the Arkansas "Balanced Treatment for Creation-Science and Evolution-Science Act" (Act 590) was unconstitutional because it violated the Establishment Clause. Much of the transcript of the case was lost, including evidence from Francisco Ayala.
Edwards v. Aguillard
In the early 1980s, the Louisiana legislature passed a law titled the "Balanced Treatment for Creation-Science and Evolution-Science Act". The act did not require teaching either evolution or creationism as such, but did require that when evolutionary science was taught, creation science had to be taught as well. Creationists had lobbied aggressively for the law, arguing that the act was about academic freedom for teachers, an argument adopted by the state in support of the act. Lower courts ruled that the State's actual purpose was to promote the religious doctrine of creation science, but the State appealed to the Supreme Court.

In the similar case of McLean v. Arkansas (see above) the federal trial court had also decided against creationism. Mclean v. Arkansas was not appealed to the federal Circuit Court of Appeals, creationists instead thinking that they had better chances with Edwards v. Aguillard. In 1987 the United States Supreme Court ruled that the Louisiana act was also unconstitutional, because the law was specifically intended to advance a particular religion. At the same time, it stated its opinion that "teaching a variety of scientific theories about the origins of humankind to school children might be validly done with the clear secular intent of enhancing the effectiveness of science instruction", leaving open the door for a handful of proponents of creation science to evolve their arguments into the iteration of creationism that later came to be known as intelligent design.

Intelligent design

The Discovery Institute's Center for the Renewal of Science and Culture used banners based on The Creation of Adam from the Sistine Chapel. Later it used a less religious image, then was renamed the Center for Science and Culture.

In response to Edwards v. Aguillard, the neo-creationist intelligent design movement was formed around the Discovery Institute's Center for Science and Culture. It makes the claim that "certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection." It has been viewed as a "scientific" approach to creationism by creationists, but is widely rejected as pseudoscience by the science community—primarily because intelligent design cannot be tested and rejected like scientific hypotheses.

Kansas evolution hearings

In the push by intelligent design advocates to introduce intelligent design in public school science classrooms, the hub of the intelligent design movement, the Discovery Institute, arranged to conduct hearings to review the evidence for evolution in the light of its Critical Analysis of Evolution lesson plans. The Kansas evolution hearings were a series of hearings held in Topeka, Kansas, May 5 to May 12, 2005. The Kansas State Board of Education eventually adopted the institute's Critical Analysis of Evolution lesson plans over objections of the State Board Science Hearing Committee, and electioneering on behalf of conservative Republican Party candidates for the Board. On August 1, 2006, four of the six conservative Republicans who approved the Critical Analysis of Evolution classroom standards lost their seats in a primary election. The moderate Republican and Democrats gaining seats vowed to overturn the 2005 school science standards and adopt those recommended by a State Board Science Hearing Committee that were rejected by the previous board, and on February 13, 2007, the Board voted 6 to 4 to reject the amended science standards enacted in 2005. The definition of science was once again limited to "the search for natural explanations for what is observed in the universe."

Dover trial

Following the Edwards v. Aguillard decision by the United States Supreme Court, in which the Court held that a Louisiana law requiring that creation science be taught in public schools whenever evolution was taught was unconstitutional, because the law was specifically intended to advance a particular religion, creationists renewed their efforts to introduce creationism into public school science classes. This effort resulted in intelligent design, which sought to avoid legal prohibitions by leaving the source of creation to an unnamed and undefined intelligent designer, as opposed to God. This ultimately resulted in the "Dover Trial," Kitzmiller v. Dover Area School District, which went to trial on 26 September 2005 and was decided on 20 December 2005 in favor of the plaintiffs, who charged that a mandate that intelligent design be taught in public school science classrooms was an unconstitutional establishment of religion. The Kitzmiller v. Dover decision held that intelligent design was not a subject of legitimate scientific research, and that it "cannot uncouple itself from its creationist, and hence religious, antecedents."

The December 2005 ruling in the Kitzmiller v. Dover Area School District trial supported the viewpoint of the American Association for the Advancement of Science and other science and education professional organizations who say that proponents of Teach the Controversy seek to undermine the teaching of evolution while promoting intelligent design, and to advance an education policy for U.S. public schools that introduces creationist explanations for the origin of life to public-school science curricula.

Texas Board of Education support for intelligent design

On March 27, 2009, the Texas Board of Education, by a vote of 13 to 2, voted that at least in Texas, textbooks must teach intelligent design alongside evolution, and question the validity of the fossil record. Don McLeroy, a dentist and chair of the board, said, "I think the new standards are wonderful ... dogmatism about evolution [has sapped] America's scientific soul." According to Science magazine, "Because Texas is the second-largest textbook market in the United States, publishers have a strong incentive to be certified by the board as 'conforming 100% to the state's standards'." The 2009 Texas Board of Education hearings were chronicled in the 2012 documentary The Revisionaries.

Recent developments

The scientific consensus on the origins and evolution of life continues to be challenged by creationist organizations and religious groups who desire to uphold some form of creationism (usually Young Earth creationism, creation science, Old Earth creationism or intelligent design) as an alternative. Most of these groups are literalist Christians who believe the biblical account is inerrant, and more than one sees the debate as part of the Christian mandate to evangelize. Some groups see science and religion as being diametrically opposed views that cannot be reconciled. More accommodating viewpoints, held by many mainstream churches and many scientists, consider science and religion to be separate categories of thought (non-overlapping magisteria), which ask fundamentally different questions about reality and posit different avenues for investigating it.

Studies on the religious beliefs of scientists does support the evidence of a rift between traditional literal fundamentalist religion and experimental science. Three studies of scientific attitudes since 1904 have shown that over 80% of scientists do not believe in a traditional god or the traditional belief in immortality, with disbelief stronger amongst biological scientists than physical scientists. Amongst those not registering such attitudes a high percentage indicated a preference for adhering to a belief concerning mystery than any dogmatic or faith based view. But only 10% of scientists stated that they saw a fundamental clash between science and religion. This study of trends over time suggests that the "culture wars" between creationism against evolution, are held more strongly by religious literalists than by scientists themselves and are likely to continue, fostering anti-scientific or pseudoscientific attitudes amongst fundamentalist believers.

More recently, the intelligent design movement has attempted an anti-evolution position that avoids any direct appeal to religion. Scientists argue that intelligent design is pseudoscience and does not represent any research program within the mainstream scientific community, and is still essentially creationism. Its leading proponent, the Discovery Institute, made widely publicized claims that it was a new science, although the only paper arguing for it published in a scientific journal was accepted in questionable circumstances and quickly disavowed in the Sternberg peer review controversy, with the Biological Society of Washington stating that it did not meet the journal's scientific standards, was a "significant departure" from the journal's normal subject area and was published at the former editor's sole discretion, "contrary to typical editorial practices." On August 1, 2005, U.S. president George W. Bush commented endorsing the teaching of intelligent design alongside evolution "I felt like both sides ought to be properly taught ... so people can understand what the debate is about."

Viewpoints

In the controversy a number of divergent opinions can be recognized, regarding both the acceptance of scientific theories and religious practice.

Young Earth creationism

Young Earth creationism is the religious belief that the Earth was created by God within the last 10,000 years, literally as described in Genesis, within the approximate timeframe of biblical genealogies (detailed for example in the Ussher chronology). Young Earth creationists often believe that the Universe has a similar age to the Earth's. Creationist cosmologies are attempts by some creationist thinkers to give the universe an age consistent with the Ussher chronology and other Young-Earth timeframes.

This belief generally has a basis in biblical literalism and completely rejects science; "creation science" is pseudoscience that attempts to prove that Young Earth creationism is consistent with science.

Old Earth creationism

Old Earth creationism holds that the physical universe was created by God, but that the creation event of Genesis within 6 days is not to be taken strictly literally. This group generally accepts the age of the Universe and the age of the Earth as described by astronomers and geologists, but that details of the evolutionary theory are questionable. Old Earth creationists interpret the Genesis creation narrative in a number of ways, each differing from the six, consecutive, 24-hour day creation of the Young Earth creationist view.

Neo-creationism

Neo-creationists intentionally distance themselves from other forms of creationism, preferring to be known as wholly separate from creationism as a philosophy. They wish to re-frame the debate over the origins of life in non-religious terms and without appeals to scripture, and to bring the debate before the public. Neo-creationists may be either Young Earth or Old Earth creationists, and hold a range of underlying theological viewpoints (e.g. on the interpretation of the Bible). Neo-creationism currently exists in the form of the intelligent design movement, which has a 'big tent' strategy making it inclusive of many Young Earth creationists (such as Paul Nelson and Percival Davis).

Theistic evolution

Theistic evolution is the general view that, instead of faith being in opposition to biological evolution, some or all classical religious teachings about God and creation are compatible with some or all of modern scientific theory, including, specifically, evolution. It generally views evolution as a tool used by a creator god, who is both the first cause and immanent sustainer/upholder of the universe; it is therefore well accepted by people of strong theistic (as opposed to deistic) convictions. Theistic evolution can synthesize with the day-age interpretation of the Genesis creation myth; most adherents consider that the first chapters of Genesis should not be interpreted as a "literal" description, but rather as a literary framework or allegory. This position generally accepts the viewpoint of methodological naturalism, a long-standing convention of the scientific method in science.

Evolution has long been accepted by many mainline/liberal denominations, yet is increasingly finding acceptance among evangelical Christians, who strive to keep traditional Christian theology intact.

Theistic evolutionists have frequently been prominent in opposing creationism (including intelligent design). Notable examples have been biologist Kenneth R. Miller and theologian John F. Haught, who testified for the plaintiffs in Kitzmiller v. Dover Area School District. Another example is the Clergy Letter Project, an organization that has created and maintains a statement signed by American Christian clergy of different denominations rejecting creationism, with specific reference to points raised by intelligent design proponents. Theistic evolutionists have also been active in Citizens Alliances for Science that oppose the introduction of creationism into public school science classes (one example being evangelical Christian geologist Keith B. Miller, who is a prominent board member of Kansas Citizens for Science).

Agnostic evolution

Agnostic evolution is the position of acceptance of biological evolution, combined with the belief that it is not important whether God is, was, or will have been involved.

Materialistic evolution

Materialistic evolution is the acceptance of biological evolution, combined with the position that if the supernatural exists, it has little to no influence on the material world (a position common to philosophical naturalists, humanists and atheists). It is a view championed by the New Atheists, who argue strongly that the creationist viewpoint is not only dangerous, but is completely rejected by science.

Arguments relating to the definition and limits of science

Critiques such as those based on the distinction between theory and fact are often leveled against unifying concepts within scientific disciplines. Principles such as uniformitarianism, Occam's razor or parsimony, and the Copernican principle are claimed to be the result of a bias within science toward philosophical naturalism, which is equated by many creationists with atheism. In countering this claim, philosophers of science use the term methodological naturalism to refer to the long-standing convention in science of the scientific method. The methodological assumption is that observable events in nature are explained only by natural causes, without assuming the existence or non-existence of the supernatural, and therefore supernatural explanations for such events are outside the realm of science. Creationists claim that supernatural explanations should not be excluded and that scientific work is paradigmatically close-minded.

Because modern science tries to rely on the minimization of a priori assumptions, error, and subjectivity, as well as on avoidance of Baconian idols, it remains neutral on subjective subjects such as religion or morality. Mainstream proponents accuse the creationists of conflating the two in a form of pseudoscience.

Theory vs. fact

The argument that evolution is a theory, not a fact, has often been made against the exclusive teaching of evolution. The argument is related to a common misconception about the technical meaning of "theory" that is used by scientists. In common usage, "theory" often refers to conjectures, hypotheses, and unproven assumptions. In science, "theory" usually means "a well-substantiated explanation of some aspect of the natural world that can incorporate facts, laws, inferences, and tested hypotheses." For comparison, the National Academy of Sciences defines a fact as "an observation that has been repeatedly confirmed and for all practical purposes is accepted as 'true'." It notes, however, that "truth in science ... is never final, and what is accepted as a fact today may be modified or even discarded tomorrow."

Exploring this issue, paleontologist Stephen Jay Gould wrote:
Evolution is a theory. It is also a fact. And facts and theories are different things, not rungs in a hierarchy of increasing certainty. Facts are the world's data. Theories are structures of ideas that explain and interpret facts. Facts do not go away when scientists debate rival theories to explain them. Einstein's theory of gravitation replaced Newton's, but apples did not suspend themselves in mid-air, pending the outcome. And humans evolved from ape-like ancestors whether they did so by Darwin's proposed mechanism or by some other yet to be discovered.
— Stephen Jay Gould, Evolution as Fact and Theory

Falsifiability

Karl Popper in the 1980s.
 
Philosopher of science Karl R. Popper set out the concept of falsifiability as a way to distinguish science and pseudoscience: testable theories are scientific, but those that are untestable are not. In Unended Quest, Popper declared "I have come to the conclusion that Darwinism is not a testable scientific theory but a metaphysical research programme, a possible framework for testable scientific theories," while pointing out it had "scientific character."

In what one sociologist derisively called "Popper-chopping," opponents of evolution seized upon Popper's definition to claim evolution was not a science, and claimed creationism was an equally valid metaphysical research program. For example, Duane Gish, a leading Creationist proponent, wrote in a letter to Discover magazine (July 1981): "Stephen Jay Gould states that creationists claim creation is a scientific theory. This is a false accusation. Creationists have repeatedly stated that neither creation nor evolution is a scientific theory (and each is equally religious)."

Popper responded to news that his conclusions were being used by anti-evolutionary forces by affirming that evolutionary theories regarding the origins of life on earth were scientific because "their hypotheses can in many cases be tested." Creationists claimed that a key evolutionary concept, that all life on Earth is descended from a single common ancestor, was not mentioned as testable by Popper, and claimed it never would be.

In fact, Popper wrote admiringly of the value of Darwin's theory. Only a few years later, Popper wrote, "I have in the past described the theory as 'almost tautological' ... I still believe that natural selection works in this way as a research programme. Nevertheless, I have changed my mind about the testability and logical status of the theory of natural selection; and I am glad to have an opportunity to make a recantation." His conclusion, later in the article is "The theory of natural selection may be so formulated that it is far from tautological. In this case it is not only testable, but it turns out to be not strictly universally true."

Debate among some scientists and philosophers of science on the applicability of falsifiability in science continues. Simple falsifiability tests for common descent have been offered by some scientists: for instance, biologist and prominent critic of creationism Richard Dawkins and J. B. S. Haldane both pointed out that if fossil rabbits were found in the Precambrian era, a time before most similarly complex lifeforms had evolved, "that would completely blow evolution out of the water."

Falsifiability has caused problems for creationists: in his 1982 decision McLean v. Arkansas Board of Education, Judge William R. Overton used falsifiability as one basis for his ruling against the teaching of creation science in the public schools, ultimately declaring it "simply not science."

Conflation of science and religion

Creationists commonly argue against evolution on the grounds that "evolution is a religion; it is not a science," in order to undermine the higher ground biologists claim in debating creationists, and to reframe the debate from being between science (evolution) and religion (creationism) to being between two equally religious beliefs—or even to argue that evolution is religious while intelligent design is not. Those that oppose evolution frequently refer to supporters of evolution as "evolutionists" or "Darwinists."

This is generally argued by analogy, by arguing that evolution and religion have one or more things in common, and that therefore evolution is a religion. Examples of claims made in such arguments are statements that evolution is based on faith, that supporters of evolution revere Darwin as a prophet, and that supporters of evolution dogmatically reject alternative suggestions out-of-hand. These claims have become more popular in recent years as the neocreationist movement has sought to distance itself from religion, thus giving it more reason to make use of a seemingly anti-religious analogy.

In response, supporters of evolution have argued that no scientist's claims, including Darwin's, are treated as sacrosanct, as shown by the aspects of Darwin's theory that have been rejected or revised by scientists over the years, to form first neo-Darwinism and later the modern evolutionary synthesis.

Appeal to consequences

A number of creationists have blurred the boundaries between their disputes over the truth of the underlying facts, and explanatory theories, of evolution, with their purported philosophical and moral consequences. This type of argument is known as an appeal to consequences, and is a logical fallacy. Examples of these arguments include those of prominent creationists such as Ken Ham and Henry M. Morris.

Disputes relating to science

Many creationists strongly oppose certain scientific theories in a number of ways, including opposition to specific applications of scientific processes, accusations of bias within the scientific community, and claims that discussions within the scientific community reveal or imply a crisis. In response to perceived crises in modern science, creationists claim to have an alternative, typically based on faith, creation science, or intelligent design. The scientific community has responded by pointing out that their conversations are frequently misrepresented (e.g. by quote mining) in order to create the impression of a deeper controversy or crisis, and that the creationists' alternatives are generally pseudoscientific.

Biology

Disputes relating to evolutionary biology are central to the controversy between creationists and the scientific community. The aspects of evolutionary biology disputed include common descent (and particularly human evolution from common ancestors with other members of the great apes), macroevolution, and the existence of transitional fossils.

Common descent

[The] Discovery [Institute] presents common descent as controversial exclusively within the animal kingdom, as it focuses on embryology, anatomy, and the fossil record to raise questions about them. In the real world of science, common descent of animals is completely noncontroversial; any controversy resides in the microbial world. There, researchers argued over a variety of topics, starting with the very beginning, namely the relationship among the three main branches of life.
— John Timmer, Evolution: what's the real controversy?
A group of organisms is said to have common descent if they have a common ancestor. A theory of universal common descent based on evolutionary principles was proposed by Charles Darwin and is now generally accepted by biologists. The most recent common ancestor of all living organisms is believed to have appeared about 3.9 billion years ago. With a few exceptions (e.g. Michael Behe) the vast majority of creationists reject this theory in favor of the belief that a common design suggests a common designer (God), for all thirty million species. Other creationists allow evolution of species, but say that it was specific "kinds" or baramin that were created. Thus all bear species may have developed from a common ancestor that was separately created.

Evidence of common descent includes evidence from genetics, fossil records, comparative anatomy, geographical distribution of species, comparative physiology and comparative biochemistry.
Human evolution
Overview of speciation and hybridization within the genus Homo over the last two million years.

Human evolution is the study of the biological evolution of humans as a distinct species from its common ancestors with other animals. Analysis of fossil evidence and genetic distance are two of the means by which scientists understand this evolutionary history.

Fossil evidence suggests that humans' earliest hominid ancestors may have split from other primates as early as the late Oligocene, circa 26 to 24 Ma, and that by the early Miocene, the adaptive radiation of many different hominoid forms was well underway. Evidence from the molecular dating of genetic differences indicates that the gibbon lineage (family Hylobatidae) diverged between 18 and 12 Ma, and the orangutan lineage (subfamily Ponginae) diverged about 12 Ma. While there is no fossil evidence thus far clearly documenting the early ancestry of gibbons, fossil proto-orangutans may be represented by Sivapithecus from India and Griphopithecus from Turkey, dated to around 10 Ma. Molecular evidence further suggests that between 8 and 4 Ma, first the gorillas, and then the chimpanzee (genus Pan) split from the line leading to the humans. We have no fossil record of this divergence, but distinctively hominid fossils have been found dating to 3.2 Ma (see Lucy) and possibly even earlier, at 6 or 7 Ma (see Toumaï). Comparisons of DNA show that 99.4 percent of the coding regions are identical in chimpanzees and humans (95–96% overall), which is taken as strong evidence of recent common ancestry. Today, only one distinct human species survives, but many earlier species have been found in the fossil record, including Homo erectus, Homo habilis, and Homo neanderthalensis

Creationists dispute there is evidence of shared ancestry in the fossil evidence, and argue either that these are misassigned ape fossils (e.g. that Java Man was a gibbon) or too similar to modern humans to designate them as distinct or transitional forms. Creationists frequently disagree where the dividing lines would be. Creation myths (such as the Book of Genesis) frequently posit a first man (Adam, in the case of Genesis) as an alternative viewpoint to the scientific account. All these claims and objections are subsequently refuted.

Creationists also dispute science's interpretation of genetic evidence in the study of human evolution. They argue that it is a "dubious assumption" that genetic similarities between various animals imply a common ancestral relationship, and that scientists are coming to this interpretation only because they have preconceived notions that such shared relationships exist. Creationists also argue that genetic mutations are strong evidence against evolutionary theory because, they assert, the mutations required for major changes to occur would almost certainly be detrimental. However, most mutations are neutral, and the minority of mutations which are beneficial or harmful are often situational; a mutation that is harmful in one environment may be helpful in another.

Macroevolution

A phylogenetic tree showing the three-domain system. Eukaryotes are colored red, archaea green, and bacteria blue.
 
In biology, macroevolution refers to evolution above the species level while microevolution refers to changes within species. However, there is no fundamental distinction between these processes; small changes compound over time and eventually lead to speciation. Creationists argue that a finite number of discrete kinds were created, as described in the Book of Genesis, and these kinds determine the limits of variation. Early Creationists equated kinds with species, but most now accept that speciation can occur: not only is the evidence overwhelming for speciation, but the millions of species now in existence could not have fit in Noah's Ark, as depicted in Genesis. Created kinds identified by creationists are more generally on the level of the family (for example, Canidae), but the genus Homo is a separate kind. A Creationist systematics called Baraminology builds on the idea of created kind, calling it a baramin. While evolutionary systematics is used to explore relationships between organisms by descent, baraminology attempts to find discontinuities between groups of organisms. It employs many of the tools of evolutionary systematics, but Biblical criteria for taxonomy take precedence over all other criteria. This undermines their claim to objectivity: they accept evidence for the common ancestry of cats or dogs but not analogous evidence for the common ancestry of apes and humans.

Recent arguments against macroevolution (in the Creationist sense) include the intelligent design (ID) arguments of irreducible complexity and specified complexity. Neither argument has been accepted for publication in a peer-reviewed scientific journal, and both arguments have been rejected by the scientific community as pseudoscience. When taken to court in an attempt to introduce ID into the classroom, the judge wrote "The overwhelming evidence at trial established that ID is a religious view, a mere re-labeling of creationism, and not a scientific theory."

Transitional fossils

It is commonly stated by critics of evolution that there are no known transitional fossils. This position is based on a misunderstanding of the nature of what represents a transitional feature. A common creationist argument is that no fossils are found with partially functional features. It is plausible that a complex feature with one function can adapt a different function through evolution. The precursor to, for example, a wing, might originally have only been used for gliding, trapping flying prey, or mating display. Today, wings can still have all of these functions, but they are also used in active flight.

Reconstruction of Ambulocetus natans
 
As another example, Alan Hayward stated in Creation and Evolution (1985) that "Darwinists rarely mention the whale because it presents them with one of their most insoluble problems. They believe that somehow a whale must have evolved from an ordinary land-dwelling animal, which took to the sea and lost its legs ... A land mammal that was in the process of becoming a whale would fall between two stools—it would not be fitted for life on land or at sea, and would have no hope for survival." The evolution of whales has been documented in considerable detail, with Ambulocetus, described as looking like a three-metre long mammalian crocodile, as one of the transitional fossils.

Although transitional fossils elucidate the evolutionary transition of one life-form to another, they only exemplify snapshots of this process. Due to the special circumstances required for preservation of living beings, only a very small percentage of all life-forms that ever have existed can be expected to be discovered. Thus, the transition itself can only be illustrated and corroborated by transitional fossils, but it will never be known in detail. Progressing research and discovery managed to fill in several gaps and continues to do so. Critics of evolution often cite this argument as being a convenient way to explain off the lack of 'snapshot' fossils that show crucial steps between species.

The theory of punctuated equilibrium developed by Stephen Jay Gould and Niles Eldredge is often mistakenly drawn into the discussion of transitional fossils. This theory pertains only to well-documented transitions within taxa or between closely related taxa over a geologically short period. These transitions, usually traceable in the same geological outcrop, often show small jumps in morphology between periods of morphological stability. To explain these jumps, Gould and Eldredge envisaged comparatively long periods of genetic stability separated by periods of rapid evolution. For example, the change from a creature the size of a mouse, to one the size of an elephant, could be accomplished over 60,000 years, with a rate of change too small to be noticed over any human lifetime. 60,000 years is too small a gap to be identified or identifiable in the fossil record.

Experts in evolutionary theory have pointed out that even if it were possible for enough fossils to survive to show a close transitional change critics will never be satisfied, as the discovery of one "missing link" itself creates two more so-called "missing links" on either side of the discovery. Richard Dawkins says that the reason for this "losing battle" is that many of these critics are theists who "simply don't want to see the truth."

Geology

Many believers in Young Earth creationism – a position held by the majority of proponents of 'flood geology' – accept biblical chronogenealogies (such as the Ussher chronology, which in turn is based on the Masoretic version of the Genealogies of Genesis). They believe that God created the universe approximately 6,000 years ago, in the space of six days. Much of creation geology is devoted to debunking the dating methods used in anthropology, geology, and planetary science that give ages in conflict with the young Earth idea. In particular, creationists dispute the reliability of radiometric dating and isochron analysis, both of which are central to mainstream geological theories of the age of the Earth. They usually dispute these methods based on uncertainties concerning initial concentrations of individually considered species and the associated measurement uncertainties caused by diffusion of the parent and daughter isotopes. A full critique of the entire parameter-fitting analysis, which relies on dozens of radionuclei parent and daughter pairs, has not been done by creationists hoping to cast doubt on the technique.

The consensus of professional scientific organizations worldwide is that no scientific evidence contradicts the age of approximately 4.5 billion years. Young Earth creationists reject these ages on the grounds of what they regard as being tenuous and untestable assumptions in the methodology. They have often quoted apparently inconsistent radiometric dates to cast doubt on the utility and accuracy of the method. Mainstream proponents who get involved in this debate point out that dating methods only rely on the assumptions that the physical laws governing radioactive decay have not been violated since the sample was formed (harking back to Lyell's doctrine of uniformitarianism). They also point out that the "problems" that creationists publicly mentioned can be shown to either not be problems at all, are issues with known contamination, or simply the result of incorrectly evaluating legitimate data. The fact that the various methods of dating give essentially identical or near identical readings is not addressed in creationism.

Other sciences

Cosmology

While Young Earth creationists believe that the Universe was created by the Judeo-Christian God approximately 6000 years ago, the current scientific consensus is that the Universe as we know it emerged from the Big Bang 13.8 billion years ago. The recent science of nucleocosmochronology is extending the approaches used for carbon-14 and other radiometric dating to the dating of astronomical features. For example, based upon this emerging science, the Galactic thin disk of the Milky Way galaxy is estimated to have been formed 8.3 ± 1.8 billion years ago.

Nuclear physics

Creationists point to experiments they have performed, which they claim demonstrate that 1.5 billion years of nuclear decay took place over a short period, from which they infer that "billion-fold speed-ups of nuclear decay" have occurred, a massive violation of the principle that radioisotope decay rates are constant, a core principle underlying nuclear physics generally, and radiometric dating in particular.

The scientific community points to numerous flaws in these experiments, to the fact that their results have not been accepted for publication by any peer-reviewed scientific journal, and to the fact that the creationist scientists conducting them were untrained in experimental geochronology.

In refutation of Young Earth claims of inconstant decay-rates affecting the reliability of radiometric dating, Roger C. Wiens, a physicist specializing in isotope dating states:
There are only three quite technical instances where a half-life changes, and these do not affect the dating methods [under discussion]":
  1. Only one technical exception occurs under terrestrial conditions, and this is not for an isotope used for dating.... The artificially-produced isotope, beryllium-7 has been shown to change by up to 1.5%, depending on its chemical environment. ... [H]eavier atoms are even less subject to these minute changes, so the dates of rocks made by electron-capture decays would only be off by at most a few hundredths of a percent.
  2. ... Another case is material inside of stars, which is in a plasma state where electrons are not bound to atoms. In the extremely hot stellar environment, a completely different kind of decay can occur. 'Bound-state beta decay' occurs when the nucleus emits an electron into a bound electronic state close to the nucleus.... All normal matter, such as everything on Earth, the Moon, meteorites, etc. has electrons in normal positions, so these instances never apply to rocks, or anything colder than several hundred thousand degrees....
  3. The last case also involves very fast-moving matter. It has been demonstrated by atomic clocks in very fast spacecraft. These atomic clocks slow down very slightly (only a second or so per year) as predicted by Einstein's theory of relativity. No rocks in our solar system are going fast enough to make a noticeable change in their dates....
    — Roger C. Wiens, Radiometric Dating, A Christian Perspective

Misrepresentations of science

The Discovery Institute has a "formal declaration" titled "A Scientific Dissent From Darwinism" which has many evangelicals, people from fields irrelevant to biology and geology and few biologists. Many of the biologists who signed have fields not directly related to evolution. Some of the biologists signed were deceived into signing the "declaration." In response, there is Project Steve.

Quote mining

As a means to criticize mainstream science, creationists sometimes quote scientists who ostensibly support the mainstream theories, but appear to acknowledge criticisms similar to those of creationists. Almost universally these have been shown to be quote mines that do not accurately reflect the evidence for evolution or the mainstream scientific community's opinion of it, or are highly out-of-date. Many of the same quotes used by creationists have appeared so frequently in Internet discussions due to the availability of cut and paste functions, that the TalkOrigins Archive has created "The Quote Mine Project" for quick reference to the original context of these quotations. Creationists often quote mine Darwin, especially with regard to the seeming improbability of the evolution of the eye, to give support to their views.

Public policy issues

The creation–evolution controversy has grown in importance in recent years, particularly as a result of the Southern strategy of the Republican Party strategist Kevin Phillips, during the Nixon and Reagan administrations in the U.S. He saw that the Civil Rights Movement had alienated many poor white southern voters of the Bible Belt and set out to capture this electorate through an alliance with the "New Right" Christian right movement.

Science education

Creationists promoted the idea that evolution is a theory in crisis with scientists criticizing evolution and claim that fairness and equal time requires educating students about the alleged scientific controversy.

Opponents, being the overwhelming majority of the scientific community and science education organizations, reply that there is no scientific controversy and that the controversy exists solely in terms of religion and politics.

George Mason University Biology Department introduced a course on the creation/evolution controversy, and apparently as students learn more about biology, they find objections to evolution less convincing, suggesting that "teaching the controversy" rightly as a separate elective course on philosophy or history of science, or "politics of science and religion," would undermine creationists' criticisms, and that the scientific community's resistance to this approach was bad public relations.

Freedom of speech

Creationists have claimed that preventing them from teaching creationism violates their right of freedom of speech. Court cases (such as Webster v. New Lenox School District (1990) and Bishop v. Aronov (1991)) have upheld school districts' and universities' right to restrict teaching to a specified curriculum.

Issues relating to religion

Religion and historical scientists

Creationists often argue that Christianity and literal belief in the Bible are either foundationally significant or directly responsible for scientific progress. To that end, Institute for Creation Research founder Henry M. Morris has enumerated scientists such as astronomer and philosopher Galileo Galilei, mathematician and theoretical physicist James Clerk Maxwell, mathematician and philosopher Blaise Pascal, geneticist monk Gregor Mendel, and Isaac Newton as believers in a biblical creation narrative.

This argument usually involves scientists who were no longer alive when evolution was proposed or whose field of study did not include evolution. The argument is generally rejected as specious by those who oppose creationism.

Many of the scientists in question did some early work on the mechanisms of evolution, e.g., the modern evolutionary synthesis combines Darwin's theory of evolution with Mendel's theories of inheritance and genetics. Though biological evolution of some sort had become the primary mode of discussing speciation within science by the late-19th century, it was not until the mid-20th century that evolutionary theories stabilized into the modern synthesis. Geneticist and evolutionary biologist Theodosius Dobzhansky, called the Father of the Modern Synthesis, argued that "Nothing in biology makes sense except in the light of evolution," and saw no conflict between evolutionary and his religious beliefs. Nevertheless, some of the historical scientists marshalled by creationists were dealing with quite different issues than any are engaged with today: Louis Pasteur, for example, opposed the theory of spontaneous generation with biogenesis, an advocacy some creationists describe as a critique on chemical evolution and abiogenesis. Pasteur accepted that some form of evolution had occurred and that the Earth was millions of years old.

The Relationship between religion and science was not portrayed in antagonistic terms until the late-19th century, and even then there have been many examples of the two being reconcilable for evolutionary scientists. Many historical scientists wrote books explaining how pursuit of science was seen by them as fulfillment of spiritual duty in line with their religious beliefs. Even so, such professions of faith were not insurance against dogmatic opposition by certain religious people.

Forums

Debates

Many creationists and scientists engage in frequent public debates regarding the origin of human life, hosted by a variety of institutions. However, some scientists disagree with this tactic, arguing that by openly debating supporters of supernatural origin explanations (creationism and intelligent design), scientists are lending credibility and unwarranted publicity to creationists, which could foster an inaccurate public perception and obscure the factual merits of the debate. For example, in May 2004 Michael Shermer debated creationist Kent Hovind in front of a predominantly creationist audience. In Shermer's online reflection while he was explaining that he won the debate with intellectual and scientific evidence he felt it was "not an intellectual exercise," but rather it was "an emotional drama," with scientists arguing from "an impregnable fortress of evidence that converges to an unmistakable conclusion," while for creationists it is "a spiritual war." While receiving positive responses from creationist observers, Shermer concluded "Unless there is a subject that is truly debatable (evolution v. creation is not), with a format that is fair, in a forum that is balanced, it only serves to belittle both the magisterium of science and the magisterium of religion." Others, like evolutionary biologist Massimo Pigliucci, have debated Hovind, and have expressed surprise to hear Hovind try "to convince the audience that evolutionists believe humans came from rocks" and at Hovind's assertion that biologists believe humans "evolved from bananas."

Bill Nye in 2014.
 
In September 2012, educator and television personality Bill Nye of Bill Nye the Science Guy fame spoke with the Associated Press and aired his fears about acceptance of creationist theory, believing that teaching children that creationism is the only true answer and without letting them understand the way science works will prevent any future innovation in the world of science. In February 2014, Nye defended evolution in the classroom in a debate with creationist Ken Ham on the topic of whether creation is a viable model of origins in today's modern, scientific era.

Eugenie Scott of the National Center for Science Education, a nonprofit organization dedicated to defending the teaching of evolution in the public schools, claimed debates are not the sort of arena to promote science to creationists. Scott says that "Evolution is not on trial in the world of science," and "the topic of the discussion should not be the scientific legitimacy of evolution" but rather should be on the lack of evidence in creationism. Stephen Jay Gould adopted a similar position, explaining:
Debate is an art form. It is about the winning of arguments. It is not about the discovery of truth. There are certain rules and procedures to debate that really have nothing to do with establishing fact—which [creationists] are very good at. Some of those rules are: never say anything positive about your own position because it can be attacked, but chip away at what appear to be the weaknesses in your opponent's position. They are good at that. I don't think I could beat the creationists at debate. I can tie them. But in courtrooms they are terrible, because in courtrooms you cannot give speeches. In a courtroom you have to answer direct questions about the positive status of your belief.
— Stephen Jay Gould, lecture 1985

Political lobbying

On both sides of the controversy a wide range of organizations are involved at a number of levels in lobbying in an attempt to influence political decisions relating to the teaching of evolution. These include the Discovery Institute, the National Center for Science Education, the National Science Teachers Association, state Citizens Alliances for Science, and numerous national science associations and state academies of science.

Media coverage

The controversy has been discussed in numerous newspaper articles, reports, op-eds and letters to the editor, as well as a number of radio and television programmes (including the PBS series, Evolution (2001) and Coral Ridge Ministries' Darwin's Deadly Legacy (2006)). This has led some commentators to express a concern at what they see as a highly inaccurate and biased understanding of evolution among the general public. Edward Humes states:
There are really two theories of evolution. There is the genuine scientific theory and there is the talk-radio pretend version, designed not to enlighten but to deceive and enrage. The talk-radio version had a packed town hall up in arms at the Why Evolution Is Stupid lecture. In this version of the theory, scientists supposedly believe that all life is accidental, a random crash of molecules that magically produced flowers, horses and humans – a scenario as unlikely as a tornado in a junkyard assembling a 747. Humans come from monkeys in this theory, just popping into existence one day. The evidence against Darwin is overwhelming, the purveyors of talk-radio evolution rail, yet scientists embrace his ideas because they want to promote atheism.
— Edward Humes, Unintelligent Designs on Darwin

Outside the United States

Views on human evolution in various countries (2008)
 
While the controversy has been prominent in the United States, it has flared up in other countries as well.

Europe

Europeans have often regarded the creation–evolution controversy as an American matter. In recent years the conflict has become an issue in other countries including Germany, the United Kingdom, Italy, the Netherlands, Poland, Turkey and Serbia.

On September 17, 2007, the Committee on Culture, Science and Education of the Parliamentary Assembly of the Council of Europe (PACE) issued a report on the attempt by American-inspired creationists to promote creationism in European schools. It concludes "If we are not careful, creationism could become a threat to human rights which are a key concern of the Council of Europe... The war on the theory of evolution and on its proponents most often originates in forms of religious extremism which are closely allied to extreme right-wing political movements... some advocates of strict creationism are out to replace democracy by theocracy." The Council of Europe firmly rejected creationism.

Australia

Under the former Queensland state government of Joh Bjelke-Petersen, in the 1980s Queensland allowed the teaching of creationism in secondary schools. In 2010, the Queensland state government introduced the topic of creationism into school classes within the "ancient history" subject where its origins and nature are discussed as a significant controversy. Public lectures have been given in rented rooms at universities, by visiting American speakers. One of the most acrimonious aspects of the Australian debate was featured on the science television program Quantum, about a long-running and ultimately unsuccessful court case by Ian Plimer, Professor of Geology at the University of Melbourne, against an ordained minister, Allen Roberts, who had claimed that there were remnants of Noah's Ark in eastern Turkey. Although the court found that Roberts had made false and misleading claims, they were not made in the course of trade or commerce, so the case failed.

Islamic countries

In recent times, the controversy has become more prominent in Islamic countries. In Egypt, evolution is currently taught in schools, but Saudi Arabia and Sudan have both banned the teaching of evolution in schools. Creation science has also been heavily promoted in Turkey and in immigrant communities in Western Europe, primarily by Harun Yahya. In Iran, traditional practice of Shia Islam isn't preoccupied with Qur'anic literalism as in case of Saudi Wahhabism but ijtihad, many influential Iranian Shi'ite scholars, including several who were closely involved in Iranian Revolution, are not opposed to evolutionary ideas in general, disagreeing that evolution necessarily conflicts with the Muslim mainstream. Iranian pupils since 5th grade of elementary school learn only about evolution, thus portraying geologists and scientists in general as an authoritative voices of scientific knowledge.

Asia

South Korea

In South Korea, most opposition to teaching evolution comes from the local evangelical community. As part of these efforts, the Korean Association for Creation Research (KACR) was established in 1981 by evangelical pastors Kim Yŏnggil and Ch‘oe Yŏngsang. In South Korea, according to a 2009 survey, about 30 percent of the population believe in creation science while opposing the teaching of evolution.

Deistic evolution

From Wikipedia, the free encyclopedia
 
Deistic evolution is a position in the origins debate which involves accepting the scientific evidence for evolution and age of the universe whilst advocating the view that a deistic God created the universe but has not interfered since. The position is a counterpoint to theistic evolution and is endorsed by those who believe in both deism and the veracity of science.

Various views on deistic evolution

In Christian Theology, by Millard J. Erickson, 2013, is written: “deistic evolution is perhaps the best way to describe one variety of what is generally called theistic evolution.” He describes it as the belief that God “began the process of evolution, producing the first matter and implanting within the creation the laws its development has followed.” Following the establishment of this process, this Creator then “withdrew from active involvement with the world, becoming, so to speak, Creator Emeritus.”
God is the Creator, the ultimate cause, but evolution is the means, the proximate cause. Thus, except for its view of the very beginning of matter, deistic evolution is identical to naturalistic evolution, for it denies that there is any direct activity by a personal God during the ongoing creative process.
Deistic evolution has little difficulty with the scientific data. There is a definite conflict, however, between deism's view of an absentee God and the biblical picture of a God who has been involved in a whole series of creative acts. In particular, both Genesis accounts of the origin of human beings indicate that God definitely and distinctly willed and acted to bring them into existence. In addition, deistic evolution conflicts with the scriptural doctrine of providence, according to which God is personally and intimately concerned with and involved in what is going on in the specific events within his entire creation.
The psychologist Steve Stewart-Williams in his book Darwin, God and the Meaning of Life (2010) states: 


Stewart-Williams further writes that deistic evolution strips God of what most religious believers consider central. Any deistic God is not around for prayers, miracles or to intervene in people's lives and that because of this it is unpopular with monotheistic religions.

Deistic Evolution adheres to the concept of some form of God, but denies any personal God. A recent defender of deistic evolution was Michael Anthony Corey, author of the book Back to Darwin: The Scientific Case for Deistic Evolution (1994). 

Some scholars have written that Charles Darwin was an advocate of deistic evolution.

Deistic evolution is similarly the operative idea in Pandeism, which has been counted amongst the handful of spiritual beliefs which "are compatible with modern science." and specifically wherein it is noted that "pandeistic belief systems .... [present] the inclusion of God as the ever unfolding expression of a complex universe with an identifiable beginning but no teleological direction necessarily present."

Theistic predeterminism

Deistic evolution is not the same as theistic evolution, yet they are sometimes confused. The difference rests on the difference between a theistic god that is interested in, if not actively involved in, the outcome of his creation and humanity specifically and a deistic god that is either disinterested in the outcome, and holds no special place for humanity, or will not intervene. Often, there is no discernible difference between the two positions—the choice of terminology has more to do with the believer and her or his need for a god, than fitting into a mostly arbitrary dictionary or academic definition.

Criticism from Christian Creationists

Deistic evolution has been criticised by Christian creationists as being incompatible with Christianity since it contradicts a literal reading of the Bible and more importantly, leaves no role for the "Christian personal God".

M. J. Erickson wrote that deistic evolution is in conflict with the scriptural doctrine of providence according to which "God is personally and intimately concerned with and involved in what is going on in the specific events within his entire creation."

Charles P. Grannan wrote in 1894, "Another baseless assumption of negative critics is that the general principles of Atheistic and Deistic evolution, admitted by many scientists to account for the origin of the various species of plants and animals, should also be applied to explain the origin of the Christian religion."

Charles Wesley Rishell criticized the concept in 1899, comparing it to the notion (false, in his view), that gravity was a property of matter instead of a continued action of God:
If evolution is God's method of creating he is still at work. Theistic Deism and evolution is possible, but deistic evolution is a contradiction in terms. Again, it is all a mere supposition that God created the world and endowed it with forces which will of necessity work out his will. It is impossible for us to say that God put forth energy in the beginning and then ceased. It is, to say the least, as probable that gravitation is a divine force constantly exerted on matter in a certain way as that it is a divine force deposited in matter once for all.
The Roman Catholic Church disagrees with the doctrine of deistic evolution. In November 2005, Pope Benedict addressed a general audience of 25,000 in St. Peter's Square:
When the Pontiff finished his address, he put his papers to one side and commented on the thought of St. Basil the Great, a Doctor of the Church, who said that some, "deceived by the atheism they bear within them, imagined the universe deprived of a guide and order, at the mercy of chance. I believe the words of this fourth-century Father are of amazing timeliness," said Benedict XVI. "How many are these 'some' today? Deceived by atheism, they believe and try to demonstrate that it is scientific to think that everything lacks a guide and order." 

Science

Deistic evolution does not oppose or contradict evolution or come into conflict with science as it says that a God started the process and then left it to natural processes. However deism is still a religious philosophy. 

Stewart-Williams wrote regarding deistic evolution and science: 


There is considerable room for this "god of the gaps" view, since scientific observation is entirely unable to shed any light on what happened during the Planck epoch, the earliest 10−43 seconds in the history of the universe. All development since this initial creative act merely follows laws and principles which He created:
  • God created the universe, perhaps using the "big bang" about 15,000 million years ago as his method. He set up basic laws to govern the running of the universe, and then left the scene entirely. God has not been seen since. The earth coalesced about 4 or 5 thousand million years ago without any input from God. Later, elementary life forms formed, which evolved into the animals and plant life that we see today through purely natural forces. It is essentially identical to naturalistic evolution, excepts that it reserves one action for God: that of initially creating the matter of the universe. This belief is common among Deists. 
  • Although the term is rarely heard, deistic evolution is perhaps the best way to describe one variety of what is generally called theistic evolution. This is the view that God began the process of evolution, producing the first matter and implanting within the creation the laws which its devel- opment has followed. Thus, he programmed the process. Then he withdrew from active involvement with the world, becoming, so to speak, Creator emeritus. The progress of the created order is free of direct influence by God. He is the Creator of everything, but only the first living form was directly created. All the rest of God's creating has been done indirectly. God is the Creator, the ultimate cause, but evolution is the means, the proximate cause. Thus, except for its view of the very beginning of matter, deistic evolution is identical to naturalistic evolution for it denies that there is any direct activity by a personal God during the ongoing creative process.

Anthropic principle

From Wikipedia, the free encyclopedia
 
The anthropic principle is a philosophical consideration that observations of the universe must be compatible with the conscious and sapient life that observes it. Proponents of the anthropic principle reason that it explains why this universe has the age and the fundamental physical constants necessary to accommodate conscious life. As a result, they believe it is unremarkable that this universe has fundamental constants that happen to fall within the narrow range thought to be compatible with life. The strong anthropic principle (SAP), as explained by John D. Barrow and Frank Tipler, states that this is all the case because the universe is in some sense compelled to eventually have conscious and sapient life emerge within it. Some critics of the SAP argue in favor of a weak anthropic principle (WAP) similar to the one defined by Brandon Carter, which states that the universe's ostensible fine tuning is the result of selection bias (specifically survivor bias): i.e., only in a universe capable of eventually supporting life will there be living beings capable of observing and reflecting on the matter. Most often such arguments draw upon some notion of the multiverse for there to be a statistical population of universes to select from and from which selection bias (our observance of only this universe, compatible with our life) could occur.

Definition and basis

The principle was formulated as a response to a series of observations that the laws of nature and parameters of the universe take on values that are consistent with conditions for life as we know it rather than a set of values that would not be consistent with life on Earth. The anthropic principle states that this is a necessity, because if life were impossible, no living entity would be there to observe it, and thus would not be known. That is, it must be possible to observe some universe, and hence, the laws and constants of any such universe must accommodate that possibility. 

The term anthropic in "anthropic principle" has been argued to be a misnomer. While singling out our kind of carbon-based life, none of the finely tuned phenomena require human life or some kind of carbon chauvinism. Any form of life or any form of heavy atom, stone, star or galaxy would do; nothing specifically human or anthropic is involved.

The anthropic principle has given rise to some confusion and controversy, partly because the phrase has been applied to several distinct ideas. All versions of the principle have been accused of discouraging the search for a deeper physical understanding of the universe. The anthropic principle is often criticized for lacking falsifiability and therefore critics of the anthropic principle may point out that the anthropic principle is a non-scientific concept, even though the weak anthropic principle, "conditions that are observed in the universe must allow the observer to exist", is "easy" to support in mathematics and philosophy, i.e. it is a tautology or truism. However, building a substantive argument based on a tautological foundation is problematic. Stronger variants of the anthropic principle are not tautologies and thus make claims considered controversial by some and that are contingent upon empirical verification.

Anthropic 'coincidences'

In 1961, Robert Dicke noted that the age of the universe, as seen by living observers, cannot be random. Instead, biological factors constrain the universe to be more or less in a "golden age", neither too young nor too old. If the universe were one tenth as old as its present age, there would not have been sufficient time to build up appreciable levels of metallicity (levels of elements besides hydrogen and helium) especially carbon, by nucleosynthesis. Small rocky planets did not yet exist. If the universe were 10 times older than it actually is, most stars would be too old to remain on the main sequence and would have turned into white dwarfs, aside from the dimmest red dwarfs, and stable planetary systems would have already come to an end. Thus, Dicke explained the coincidence between large dimensionless numbers constructed from the constants of physics and the age of the universe, a coincidence which had inspired Dirac's varying-G theory

Dicke later reasoned that the density of matter in the universe must be almost exactly the critical density needed to prevent the Big Crunch (the "Dicke coincidences" argument). The most recent measurements may suggest that the observed density of baryonic matter, and some theoretical predictions of the amount of dark matter account for about 30% of this critical density, with the rest contributed by a cosmological constant. Steven Weinberg gave an anthropic explanation for this fact: he noted that the cosmological constant has a remarkably low value, some 120 orders of magnitude smaller than the value particle physics predicts (this has been described as the "worst prediction in physics"). However, if the cosmological constant were only several orders of magnitude larger than its observed value, the universe would suffer catastrophic inflation, which would preclude the formation of stars, and hence life. 

The observed values of the dimensionless physical constants (such as the fine-structure constant) governing the four fundamental interactions are balanced as if fine-tuned to permit the formation of commonly found matter and subsequently the emergence of life. A slight increase in the strong interaction would bind the dineutron and the diproton and convert all hydrogen in the early universe to helium; likewise, an increase in the weak interaction also would convert all hydrogen to helium. Water, as well as sufficiently long-lived stable stars, both essential for the emergence of life as we know it, would not exist. More generally, small changes in the relative strengths of the four fundamental interactions can greatly affect the universe's age, structure, and capacity for life.

Origin

The phrase "anthropic principle" first appeared in Brandon Carter's contribution to a 1973 Kraków symposium honouring Copernicus's 500th birthday. Carter, a theoretical astrophysicist, articulated the Anthropic Principle in reaction to the Copernican Principle, which states that humans do not occupy a privileged position in the Universe. As Carter said: "Although our situation is not necessarily central, it is inevitably privileged to some extent." Specifically, Carter disagreed with using the Copernican principle to justify the Perfect Cosmological Principle, which states that all large regions and times in the universe must be statistically identical. The latter principle underlay the steady-state theory, which had recently been falsified by the 1965 discovery of the cosmic microwave background radiation. This discovery was unequivocal evidence that the universe has changed radically over time (for example, via the Big Bang). 

Carter defined two forms of the anthropic principle, a "weak" one which referred only to anthropic selection of privileged spacetime locations in the universe, and a more controversial "strong" form which addressed the values of the fundamental constants of physics.
Roger Penrose explained the weak form as follows:
The argument can be used to explain why the conditions happen to be just right for the existence of (intelligent) life on the Earth at the present time. For if they were not just right, then we should not have found ourselves to be here now, but somewhere else, at some other appropriate time. This principle was used very effectively by Brandon Carter and Robert Dicke to resolve an issue that had puzzled physicists for a good many years. The issue concerned various striking numerical relations that are observed to hold between the physical constants (the gravitational constant, the mass of the proton, the age of the universe, etc.). A puzzling aspect of this was that some of the relations hold only at the present epoch in the Earth's history, so we appear, coincidentally, to be living at a very special time (give or take a few million years!). This was later explained, by Carter and Dicke, by the fact that this epoch coincided with the lifetime of what are called main-sequence stars, such as the Sun. At any other epoch, the argument ran, there would be no intelligent life around to measure the physical constants in question—so the coincidence had to hold, simply because there would be intelligent life around only at the particular time that the coincidence did hold!
— The Emperor's New Mind, Chapter 10
One reason this is plausible is that there are many other places and times in which we can imagine finding ourselves. But when applying the strong principle, we only have one universe, with one set of fundamental parameters, so what exactly is the point being made? Carter offers two possibilities: First, we can use our own existence to make "predictions" about the parameters. But second, "as a last resort", we can convert these predictions into explanations by assuming that there is more than one universe, in fact a large and possibly infinite collection of universes, something that is now called the multiverse ("world ensemble" was Carter's term), in which the parameters (and perhaps the laws of physics) vary across universes. The strong principle then becomes an example of a selection effect, exactly analogous to the weak principle. Postulating a multiverse is certainly a radical step, but taking it could provide at least a partial answer to a question which had seemed to be out of the reach of normal science: "why do the fundamental laws of physics take the particular form we observe and not another?" 

Since Carter's 1973 paper, the term "anthropic principle" has been extended to cover a number of ideas which differ in important ways from those he espoused. Particular confusion was caused in 1986 by the book The Anthropic Cosmological Principle by John D. Barrow and Frank Tipler, published that year which distinguished between "weak" and "strong" anthropic principle in a way very different from Carter's, as discussed in the next section.

Carter was not the first to invoke some form of the anthropic principle. In fact, the evolutionary biologist Alfred Russel Wallace anticipated the anthropic principle as long ago as 1904: "Such a vast and complex universe as that which we know exists around us, may have been absolutely required [...] in order to produce a world that should be precisely adapted in every detail for the orderly development of life culminating in man." In 1957, Robert Dicke wrote: "The age of the Universe 'now' is not random but conditioned by biological factors [...] [changes in the values of the fundamental constants of physics] would preclude the existence of man to consider the problem."

Variants

Weak anthropic principle (WAP) (Carter): "[W]e must be prepared to take account of the fact that our location in the universe is necessarily privileged to the extent of being compatible with our existence as observers." Note that for Carter, "location" refers to our location in time as well as space.
Strong anthropic principle (SAP) (Carter): "[T]he universe (and hence the fundamental parameters on which it depends) must be such as to admit the creation of observers within it at some stage. To paraphrase Descartes, cogito ergo mundus talis est."

The Latin tag ("I think, therefore the world is such [as it is]") makes it clear that "must" indicates a deduction from the fact of our existence; the statement is thus a truism

In their 1986 book, The Anthropic Cosmological Principle, John Barrow and Frank Tipler depart from Carter and define the WAP and SAP as follows:

Weak anthropic principle (WAP) (Barrow and Tipler): "The observed values of all physical and cosmological quantities are not equally probable but they take on values restricted by the requirement that there exist sites where carbon-based life can evolve and by the requirements that the universe be old enough for it to have already done so."

Unlike Carter they restrict the principle to carbon-based life, rather than just "observers". A more important difference is that they apply the WAP to the fundamental physical constants, such as the fine structure constant, the number of spacetime dimensions, and the cosmological constant—topics that fall under Carter's SAP.

Strong anthropic principle (SAP) (Barrow and Tipler): "The Universe must have those properties which allow life to develop within it at some stage in its history."

This looks very similar to Carter's SAP, but unlike the case with Carter's SAP, the "must" is an imperative, as shown by the following three possible elaborations of the SAP, each proposed by Barrow and Tipler:
  • "There exists one possible Universe 'designed' with the goal of generating and sustaining 'observers'."
This can be seen as simply the classic design argument restated in the garb of contemporary cosmology. It implies that the purpose of the universe is to give rise to intelligent life, with the laws of nature and their fundamental physical constants set to ensure that life as we know it will emerge and evolve.
  • "Observers are necessary to bring the Universe into being."
Barrow and Tipler believe that this is a valid conclusion from quantum mechanics, as John Archibald Wheeler has suggested, especially via his idea that information is the fundamental reality (see It from bit) and his Participatory anthropic principle (PAP) which is an interpretation of quantum mechanics associated with the ideas of John von Neumann and Eugene Wigner.
  • "An ensemble of other different universes is necessary for the existence of our Universe."
By contrast, Carter merely says that an ensemble of universes is necessary for the SAP to count as an explanation.
The philosophers John Leslie and Nick Bostrom reject the Barrow and Tipler SAP as a fundamental misreading of Carter. For Bostrom, Carter's anthropic principle just warns us to make allowance for anthropic bias—that is, the bias created by anthropic selection effects (which Bostrom calls "observation" selection effects)—the necessity for observers to exist in order to get a result. He writes:
Many 'anthropic principles' are simply confused. Some, especially those drawing inspiration from Brandon Carter's seminal papers, are sound, but... they are too weak to do any real scientific work. In particular, I argue that existing methodology does not permit any observational consequences to be derived from contemporary cosmological theories, though these theories quite plainly can be and are being tested empirically by astronomers. What is needed to bridge this methodological gap is a more adequate formulation of how observation selection effects are to be taken into account.
— Anthropic Bias, Introduction
Strong self-sampling assumption (SSSA) (Bostrom): "Each observer-moment should reason as if it were randomly selected from the class of all observer-moments in its reference class."

Analysing an observer's experience into a sequence of "observer-moments" helps avoid certain paradoxes; but the main ambiguity is the selection of the appropriate "reference class": for Carter's WAP this might correspond to all real or potential observer-moments in our universe; for the SAP, to all in the multiverse. Bostrom's mathematical development shows that choosing either too broad or too narrow a reference class leads to counter-intuitive results, but he is not able to prescribe an ideal choice.

According to Jürgen Schmidhuber, the anthropic principle essentially just says that the conditional probability of finding yourself in a universe compatible with your existence is always 1. It does not allow for any additional nontrivial predictions such as "gravity won't change tomorrow". To gain more predictive power, additional assumptions on the prior distribution of alternative universes are necessary.

Playwright and novelist Michael Frayn describes a form of the Strong Anthropic Principle in his 2006 book The Human Touch, which explores what he characterises as "the central oddity of the Universe":
It's this simple paradox. The Universe is very old and very large. Humankind, by comparison, is only a tiny disturbance in one small corner of it – and a very recent one. Yet the Universe is only very large and very old because we are here to say it is... And yet, of course, we all know perfectly well that it is what it is whether we are here or not.

Character of anthropic reasoning

Carter chose to focus on a tautological aspect of his ideas, which has resulted in much confusion. In fact, anthropic reasoning interests scientists because of something that is only implicit in the above formal definitions, namely that we should give serious consideration to there being other universes with different values of the "fundamental parameters"—that is, the dimensionless physical constants and initial conditions for the Big Bang. Carter and others have argued that life as we know it would not be possible in most such universes. In other words, the universe we are in is fine tuned to permit life. Collins & Hawking (1973) characterized Carter's then-unpublished big idea as the postulate that "there is not one universe but a whole infinite ensemble of universes with all possible initial conditions". If this is granted, the anthropic principle provides a plausible explanation for the fine tuning of our universe: the "typical" universe is not fine-tuned, but given enough universes, a small fraction thereof will be capable of supporting intelligent life. Ours must be one of these, and so the observed fine tuning should be no cause for wonder.

Although philosophers have discussed related concepts for centuries, in the early 1970s the only genuine physical theory yielding a multiverse of sorts was the many-worlds interpretation of quantum mechanics. This would allow variation in initial conditions, but not in the truly fundamental constants. Since that time a number of mechanisms for producing a multiverse have been suggested: see the review by Max Tegmark. An important development in the 1980s was the combination of inflation theory with the hypothesis that some parameters are determined by symmetry breaking in the early universe, which allows parameters previously thought of as "fundamental constants" to vary over very large distances, thus eroding the distinction between Carter's weak and strong principles. At the beginning of the 21st century, the string landscape emerged as a mechanism for varying essentially all the constants, including the number of spatial dimensions.

The anthropic idea that fundamental parameters are selected from a multitude of different possibilities (each actual in some universe or other) contrasts with the traditional hope of physicists for a theory of everything having no free parameters. As Einstein said: "What really interests me is whether God had any choice in the creation of the world." In 2002, proponents of the leading candidate for a "theory of everything", string theory, proclaimed "the end of the anthropic principle" since there would be no free parameters to select. String theory now seems to offer no hope of predicting fundamental parameters, and now some who advocate it invoke the anthropic principle as well.

The modern form of a design argument is put forth by intelligent design. Proponents of intelligent design often cite the fine-tuning observations that (in part) preceded the formulation of the anthropic principle by Carter as a proof of an intelligent designer. Opponents of intelligent design are not limited to those who hypothesize that other universes exist; they may also argue, anti-anthropically, that the universe is less fine-tuned than often claimed, or that accepting fine tuning as a brute fact is less astonishing than the idea of an intelligent creator. Furthermore, even accepting fine tuning, Sober (2005) and Ikeda and Jefferys, argue that the Anthropic Principle as conventionally stated actually undermines intelligent design. 

Paul Davies's book The Goldilocks Enigma (2006) reviews the current state of the fine tuning debate in detail, and concludes by enumerating the following responses to that debate:
  1. The absurd universe: Our universe just happens to be the way it is.
  2. The unique universe: There is a deep underlying unity in physics which necessitates the Universe being the way it is. Some Theory of Everything will explain why the various features of the Universe must have exactly the values that we see.
  3. The multiverse: Multiple universes exist, having all possible combinations of characteristics, and we inevitably find ourselves within a universe that allows us to exist.
  4. Intelligent design: A creator designed the Universe with the purpose of supporting complexity and the emergence of intelligence.
  5. The life principle: There is an underlying principle that constrains the Universe to evolve towards life and mind.
  6. The self-explaining universe: A closed explanatory or causal loop: "perhaps only universes with a capacity for consciousness can exist". This is Wheeler's Participatory Anthropic Principle (PAP).
  7. The fake universe: We live inside a virtual reality simulation.
Omitted here is Lee Smolin's model of cosmological natural selection, also known as "fecund universes", which proposes that universes have "offspring" which are more plentiful if they resemble our universe. Also see Gardner (2005).

Clearly each of these hypotheses resolve some aspects of the puzzle, while leaving others unanswered. Followers of Carter would admit only option 3 as an anthropic explanation, whereas 3 through 6 are covered by different versions of Barrow and Tipler's SAP (which would also include 7 if it is considered a variant of 4, as in Tipler 1994).

The anthropic principle, at least as Carter conceived it, can be applied on scales much smaller than the whole universe. For example, Carter (1983) inverted the usual line of reasoning and pointed out that when interpreting the evolutionary record, one must take into account cosmological and astrophysical considerations. With this in mind, Carter concluded that given the best estimates of the age of the universe, the evolutionary chain culminating in Homo sapiens probably admits only one or two low probability links.

Observational evidence

No possible observational evidence bears on Carter's WAP, as it is merely advice to the scientist and asserts nothing debatable. The obvious test of Barrow's SAP, which says that the universe is "required" to support life, is to find evidence of life in universes other than ours. Any other universe is, by most definitions, unobservable (otherwise it would be included in our portion of this universe). Thus, in principle Barrow's SAP cannot be falsified by observing a universe in which an observer cannot exist.

Philosopher John Leslie states that the Carter SAP (with multiverse) predicts the following:
  • Physical theory will evolve so as to strengthen the hypothesis that early phase transitions occur probabilistically rather than deterministically, in which case there will be no deep physical reason for the values of fundamental constants;
  • Various theories for generating multiple universes will prove robust;
  • Evidence that the universe is fine tuned will continue to accumulate;
  • No life with a non-carbon chemistry will be discovered;
  • Mathematical studies of galaxy formation will confirm that it is sensitive to the rate of expansion of the universe.
Hogan has emphasised that it would be very strange if all fundamental constants were strictly determined, since this would leave us with no ready explanation for apparent fine tuning. In fact we might have to resort to something akin to Barrow and Tipler's SAP: there would be no option for such a universe not to support life. 

Probabilistic predictions of parameter values can be made given:
  1. a particular multiverse with a "measure", i.e. a well defined "density of universes" (so, for parameter X, one can calculate the prior probability P(X0) dX that X is in the range X0 < X < X0 + dX), and
  2. an estimate of the number of observers in each universe, N(X) (e.g., this might be taken as proportional to the number of stars in the universe).
The probability of observing value X is then proportional to N(X) P(X). A generic feature of an analysis of this nature is that the expected values of the fundamental physical constants should not be "over-tuned", i.e. if there is some perfectly tuned predicted value (e.g. zero), the observed value need be no closer to that predicted value than what is required to make life possible. The small but finite value of the cosmological constant can be regarded as a successful prediction in this sense. 

One thing that would not count as evidence for the Anthropic Principle is evidence that the Earth or the Solar System occupied a privileged position in the universe, in violation of the Copernican principle (for possible counterevidence to this principle, see Copernican principle), unless there was some reason to think that that position was a necessary condition for our existence as observers.

Applications of the principle

The nucleosynthesis of carbon-12

Fred Hoyle may have invoked anthropic reasoning to predict an astrophysical phenomenon. He is said to have reasoned from the prevalence on Earth of life forms whose chemistry was based on carbon-12 atoms, that there must be an undiscovered resonance in the carbon-12 nucleus facilitating its synthesis in stellar interiors via the triple-alpha process. He then calculated the energy of this undiscovered resonance to be 7.6 million electronvolts. Willie Fowler's research group soon found this resonance, and its measured energy was close to Hoyle's prediction. 

However, in 2010 Helge Kragh argued that Hoyle did not use anthropic reasoning in making his prediction, since he made his prediction in 1953 and anthropic reasoning did not come into prominence until 1980. He called this an "anthropic myth," saying that Hoyle and others made an after-the-fact connection between carbon and life decades after the discovery of the resonance.
An investigation of the historical circumstances of the prediction and its subsequent experimental confirmation shows that Hoyle and his contemporaries did not associate the level in the carbon nucleus with life at all.

Cosmic inflation

Don Page criticized the entire theory of cosmic inflation as follows. He emphasized that initial conditions which made possible a thermodynamic arrow of time in a universe with a Big Bang origin, must include the assumption that at the initial singularity, the entropy of the universe was low and therefore extremely improbable. Paul Davies rebutted this criticism by invoking an inflationary version of the anthropic principle. While Davies accepted the premise that the initial state of the visible universe (which filled a microscopic amount of space before inflating) had to possess a very low entropy value—due to random quantum fluctuations—to account for the observed thermodynamic arrow of time, he deemed this fact an advantage for the theory. That the tiny patch of space from which our observable universe grew had to be extremely orderly, to allow the post-inflation universe to have an arrow of time, makes it unnecessary to adopt any "ad hoc" hypotheses about the initial entropy state, hypotheses other Big Bang theories require.

String theory

String theory predicts a large number of possible universes, called the "backgrounds" or "vacua". The set of these vacua is often called the "multiverse" or "anthropic landscape" or "string landscape". Leonard Susskind has argued that the existence of a large number of vacua puts anthropic reasoning on firm ground: only universes whose properties are such as to allow observers to exist are observed, while a possibly much larger set of universes lacking such properties go unnoticed.

Steven Weinberg believes the Anthropic Principle may be appropriated by cosmologists committed to nontheism, and refers to that Principle as a "turning point" in modern science because applying it to the string landscape "may explain how the constants of nature that we observe can take values suitable for life without being fine-tuned by a benevolent creator". Others—most notably David Gross but also Lubos Motl, Peter Woit, and Lee Smolin—argue that this is not predictive. Max Tegmark, Mario Livio, and Martin Rees argue that only some aspects of a physical theory need be observable and/or testable for the theory to be accepted, and that many well-accepted theories are far from completely testable at present.

Jürgen Schmidhuber (2000–2002) points out that Ray Solomonoff's theory of universal inductive inference and its extensions already provide a framework for maximizing our confidence in any theory, given a limited sequence of physical observations, and some prior distribution on the set of possible explanations of the universe.

Dimensions of spacetime

Properties of n+m-dimensional spacetimes
 
There are two kinds of dimensions, spatial (bidirectional) and temporal (unidirectional). Let the number of spatial dimensions be N and the number of temporal dimensions be T. That N = 3 and T = 1, setting aside the compactified dimensions invoked by string theory and undetectable to date, can be explained by appealing to the physical consequences of letting N differ from 3 and T differ from 1. The argument is often of an anthropic character and possibly the first of its kind, albeit before the complete concept came into vogue. 

The implicit notion that the dimensionality of the universe is special is first attributed to Gottfried Wilhelm Leibniz, who in the Discourse on Metaphysics suggested that the world is "the one which is at the same time the simplest in hypothesis and the richest in phenomena". Immanuel Kant argued that 3-dimensional space was a consequence of the inverse square law of universal gravitation. While Kant's argument is historically important, John D. Barrow says that it "gets the punch-line back to front: it is the three-dimensionality of space that explains why we see inverse-square force laws in Nature, not vice-versa" (Barrow 2002: 204).

In 1920, Paul Ehrenfest showed that if there is only one time dimension and greater than three spatial dimensions, the orbit of a planet about its Sun cannot remain stable. The same is true of a star's orbit around the center of its galaxy. Ehrenfest also showed that if there are an even number of spatial dimensions, then the different parts of a wave impulse will travel at different speeds. If there are spatial dimensions, where k is a positive whole number, then wave impulses become distorted. In 1922, Hermann Weyl showed that Maxwell's theory of electromagnetism works only with three dimensions of space and one of time. Finally, Tangherlini showed in 1963 that when there are more than three spatial dimensions, electron orbitals around nuclei cannot be stable; electrons would either fall into the nucleus or disperse.

Max Tegmark expands on the preceding argument in the following anthropic manner. If T differs from 1, the behavior of physical systems could not be predicted reliably from knowledge of the relevant partial differential equations. In such a universe, intelligent life capable of manipulating technology could not emerge. Moreover, if T > 1, Tegmark maintains that protons and electrons would be unstable and could decay into particles having greater mass than themselves. (This is not a problem if the particles have a sufficiently low temperature.) If N < 3, gravitation of any kind becomes problematic, and the universe is probably too simple to contain observers. For example, when N < 3, nerves cannot cross without intersecting.

In general, it is not clear how physical law could function if T differed from 1. If T > 1, subatomic particles which decay after a fixed period would not behave predictably, because time-like geodesics would not be necessarily maximal. N = 1 and T = 3 has the peculiar property that the speed of light in a vacuum is a lower bound on the velocity of matter; all matter consists of tachyons.

Hence anthropic and other arguments rule out all cases except N = 3 and T = 1, which happens to describe the world around us.

Metaphysical interpretations

Some of the metaphysical disputes and speculations include, for example, attempts to back Pierre Teilhard de Chardin's earlier interpretation of the universe as being Christ centered (compare Omega Point), expressing a creatio evolutiva instead the elder notion of creatio continua. From a strictly secular, humanist perspective, it allows as well to put human beings back in the center, an anthropogenic shift in cosmology. Karl W. Giberson has been sort of laconic in stating that
What emerges is the suggestion that cosmology may at last be in possession of some raw material for a postmodern creation myth.

The Anthropic Cosmological Principle

A thorough extant study of the anthropic principle is the book The Anthropic Cosmological Principle by John D. Barrow, a cosmologist, and Frank J. Tipler, a cosmologist and mathematical physicist. This book sets out in detail the many known anthropic coincidences and constraints, including many found by its authors. While the book is primarily a work of theoretical astrophysics, it also touches on quantum physics, chemistry, and earth science. An entire chapter argues that Homo sapiens is, with high probability, the only intelligent species in the Milky Way.

The book begins with an extensive review of many topics in the history of ideas the authors deem relevant to the anthropic principle, because the authors believe that principle has important antecedents in the notions of teleology and intelligent design. They discuss the writings of Fichte, Hegel, Bergson, and Alfred North Whitehead, and the Omega Point cosmology of Teilhard de Chardin. Barrow and Tipler carefully distinguish teleological reasoning from eutaxiological reasoning; the former asserts that order must have a consequent purpose; the latter asserts more modestly that order must have a planned cause. They attribute this important but nearly always overlooked distinction to an obscure 1883 book by L. E. Hicks.

Seeing little sense in a principle requiring intelligent life to emerge while remaining indifferent to the possibility of its eventual extinction, Barrow and Tipler propose the final anthropic principle (FAP): Intelligent information-processing must come into existence in the universe, and, once it comes into existence, it will never die out.

Barrow and Tipler submit that the FAP is both a valid physical statement and "closely connected with moral values". FAP places strong constraints on the structure of the universe, constraints developed further in Tipler's The Physics of Immortality. One such constraint is that the universe must end in a Big Crunch, which seems unlikely in view of the tentative conclusions drawn since 1998 about dark energy, based on observations of very distant supernovas

In his review of Barrow and Tipler, Martin Gardner ridiculed the FAP by quoting the last two sentences of their book as defining a Completely Ridiculous Anthropic Principle (CRAP):
At the instant the Omega Point is reached, life will have gained control of all matter and forces not only in a single universe, but in all universes whose existence is logically possible; life will have spread into all spatial regions in all universes which could logically exist, and will have stored an infinite amount of information, including all bits of knowledge which it is logically possible to know. And this is the end.

Reception and controversies

Carter has frequently regretted his own choice of the word "anthropic", because it conveys the misleading impression that the principle involves humans specifically, rather than intelligent observers in general. Others have criticised the word "principle" as being too grandiose to describe straightforward applications of selection effects.

A common criticism of Carter's SAP is that it is an easy deus ex machina which discourages searches for physical explanations. To quote Penrose again: "[I]t tends to be invoked by theorists whenever they do not have a good enough theory to explain the observed facts."

Carter's SAP and Barrow and Tipler's WAP have been dismissed as truisms or trivial tautologies—that is, statements true solely by virtue of their logical form (the conclusion is identical to the premise) and not because a substantive claim is made and supported by observation of reality. As such, they are criticized as an elaborate way of saying "if things were different, they would be different", which is a valid statement, but does not make a claim of some factual alternative over another.

Critics of the Barrow and Tipler SAP claim that it is neither testable nor falsifiable, and thus is not a scientific statement but rather a philosophical one. The same criticism has been leveled against the hypothesis of a multiverse, although some argue that it does make falsifiable predictions. A modified version of this criticism is that we understand so little about the emergence of life, especially intelligent life, that it is effectively impossible to calculate the number of observers in each universe. Also, the prior distribution of universes as a function of the fundamental constants is easily modified to get any desired result.

Many criticisms focus on versions of the strong anthropic principle, such as Barrow and Tipler's anthropic cosmological principle, which are teleological notions that tend to describe the existence of life as a necessary prerequisite for the observable constants of physics. Similarly, Stephen Jay Gould, Michael Shermer, and others claim that the stronger versions of the anthropic principle seem to reverse known causes and effects. Gould compared the claim that the universe is fine-tuned for the benefit of our kind of life to saying that sausages were made long and narrow so that they could fit into modern hotdog buns, or saying that ships had been invented to house barnacles. These critics cite the vast physical, fossil, genetic, and other biological evidence consistent with life having been fine-tuned through natural selection to adapt to the physical and geophysical environment in which life exists. Life appears to have adapted to the universe, and not vice versa.

Some applications of the anthropic principle have been criticized as an argument by lack of imagination, for tacitly assuming that carbon compounds and water are the only possible chemistry of life (sometimes called "carbon chauvinism", see also alternative biochemistry). The range of fundamental physical constants consistent with the evolution of carbon-based life may also be wider than those who advocate a fine tuned universe have argued. For instance, Harnik et al. propose a weakless universe in which the weak nuclear force is eliminated. They show that this has no significant effect on the other fundamental interactions, provided some adjustments are made in how those interactions work. However, if some of the fine-tuned details of our universe were violated, that would rule out complex structures of any kind—stars, planets, galaxies, etc.

Lee Smolin has offered a theory designed to improve on the lack of imagination that anthropic principles have been accused of. He puts forth his fecund universes theory, which assumes universes have "offspring" through the creation of black holes whose offspring universes have values of physical constants that depend on those of the mother universe.

The philosophers of cosmology John Earman, Ernan McMullin, and Jesús Mosterín contend that "in its weak version, the anthropic principle is a mere tautology, which does not allow us to explain anything or to predict anything that we did not already know. In its strong version, it is a gratuitous speculation". A further criticism by Mosterín concerns the flawed "anthropic" inference from the assumption of an infinity of worlds to the existence of one like ours:
The suggestion that an infinity of objects characterized by certain numbers or properties implies the existence among them of objects with any combination of those numbers or characteristics [...] is mistaken. An infinity does not imply at all that any arrangement is present or repeated. [...] The assumption that all possible worlds are realized in an infinite universe is equivalent to the assertion that any infinite set of numbers contains all numbers (or at least all Gödel numbers of the [defining] sequences), which is obviously false.

Operator (computer programming)

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