"From each according to his ability, to each according to his needs" (German: Jeder nach seinen Fähigkeiten, jedem nach seinen Bedürfnissen) is a slogan popularised by Karl Marx in his 1875 Critique of the Gotha Program.
The principle refers to free access to and distribution of goods,
capital and services. In the Marxist view, such an arrangement will be
made possible by the abundance of goods and services that a developed communist system will be capable to produce; the idea is that, with the full development of socialism and unfettered productive forces, there will be enough to satisfy everyone's needs.
Origin of the phrase
The complete paragraph containing Marx's statement of the creed in the Critique of the Gotha Program is as follows:
In
a higher phase of communist society, after the enslaving subordination
of the individual to the division of labor, and therewith also the
antithesis between mental and physical labor, has vanished; after labor
has become not only a means of life but life's prime want; after the
productive forces have also increased with the all-around development of
the individual, and all the springs of co-operative wealth flow more
abundantly—only then can the narrow horizon of bourgeois right be
crossed in its entirety and society inscribe on its banners: From each according to his ability, to each according to his needs!
Although Marx is popularly thought of as the originator of the
phrase, the slogan was common within the socialist movement. For
example, August Becker in 1844 described it as the basic principle of communism and Louis Blanc used it in 1851. The French socialist Saint-Simonists of the 1820s and 1830s used slightly different slogans such as," from each according to his ability, to each ability according to its work"or,"
From each according to his capacity, to each according to his works.”
The origin of this phrasing has also been attributed to the French
utopian Étienne-Gabriel Morelly, who proposed in his 1755 Code of Nature "Sacred and Fundamental Laws that would tear out the roots of vice and of all the evils of a society", including:
I.
Nothing in society will belong to anyone, either as a personal
possession or as capital goods, except the things for which the person
has immediate use, for either his needs, his pleasures, or his daily
work. II. Every citizen will be a public man, sustained by, supported by, and occupied at the public expense. III.
Every citizen will make his particular contribution to the activities
of the community according to his capacity, his talent and his age; it
is on this basis that his duties will be determined, in conformity with
the distributive laws.
We
whose names are here underwritten, intending by God's gracious
permission to plant ourselves in New England, and if it may be, in the
southerly part about Quinnipiack, do faithfully promise each, for
ourselves and our families and those that belong to us, that we will,
the Lord assisting us, sit down and join ourselves together in one
entire plantation, and be helpful each to the other in any common work, according to every man's ability, and as need shall require,
and we promise not to desert or leave each other or the plantation, but
with the consent of the rest, or the greater part of the company who
have entered into this engagement.
Some scholars trace the phrase to the New Testament. In Acts of the Apostles
the lifestyle of the community of believers in Jerusalem is described
as communal (without individual possession), and uses the phrase "distribution was made unto every man according as he had need" (διεδίδετο δὲ ἑκάστῳ καθότι ἄν τις χρείαν εἶχεν):
Acts
4:32–35: ³² And the multitude of them that believed were of one heart
and of one soul: neither said any of them that ought of the things which
he possessed was his own; but they had all things common. ³³ And with
great power gave the apostles witness of the resurrection of the Lord
Jesus: and great grace was upon them all. ³⁴ Neither was there any among
them that lacked: for as many as were possessors of lands or houses
sold them, and brought the prices of the things that were sold, ³⁵ And
laid them down at the apostles' feet: and distribution was made unto
every man according as he had need.
Other scholars find its origins in "the Roman legal concept of obligation in solidum",
in which "everyone assumes responsibility for anyone who cannot pay his
debt, and he is conversely responsible for everyone else". James Furner argues:
If x = a disadvantage, and y = action to redress that disadvantage,
the principle of solidarity is: if any member of a group acquires x,
each member has a duty to perform y (if they can assist). All we then
need to add, to get to the fundamental principle of developed communism,
is to assume that non-satisfaction of a need is a disadvantage. The
corresponding principle of solidarity in respect of need says: if any
member of society has an unsatisfied need, each member has a duty to
produce its object (if they can). But that is precisely what the
principle 'from each according to their abilities, to each according to
their needs!' dictates. In Marx's vision, the basic principle of
developed communism is a principle of solidarity in respect of need.
Debates on the idea
Marx
delineated the specific conditions under which such a creed would be
applicable—a society where technology and social organization had
substantially eliminated the need for physical labor in the production
of things, where "labor has become not only a means of life but life's
prime want".
Marx explained his belief that, in such a society, each person would be
motivated to work for the good of society despite the absence of a
social mechanism compelling them to work, because work would have
become a pleasurable and creative activity. Marx intended the initial
part of his slogan, "from each according to his ability" to suggest not
merely that each person should work as hard as they can, but that each
person should best develop their particular talents.
Claiming themselves to be at a "lower stage of communism" (i.e. "socialism", in line with Vladimir Lenin’s terminology), the Soviet Union adapted the formula as: "From each according to his ability, to each according to his work (labour investment)". This was incorporated in Article 12 of the 1936 Constitution of the Soviet Union, but described by Leon Trotsky as "This inwardly contradictory, not to say nonsensical, formula".
While liberation theology
has sought to interpret the Christian call for justice in a way that is
in harmony with this Marxist dictum, many have noted that Jesus'
teaching in the Parable of the Talents (Matthew 25:14–30) affirms only "TO each according to his ability" (Matt. 25:15), and not "FROM each according to his ability".There are Christian authors and denominations who believe Marxist
thought to be antithetical to Christian doctrine due to Christian's
voluntary membership and adherence to the worldview's teachings, as
defined through Barna Group research.
In popular culture
In Ayn Rand's 1957 novel Atlas Shrugged,
a large and profitable motor company adopted this slogan as its method
for determining employee compensation. The system quickly fell prey to
corruption and greed, forcing the most capable employees to work
overtime in order to satisfy the needs of the least competent and to
funnel money to the owners. As a result, the company went bankrupt
within four years.
In Margaret Atwood's 1985 novel The Handmaid's Tale, members of a dystopian society recited the phrase thrice daily.
Notably the phrase is altered to read "From each according to her
ability; to each according to his need", demonstrating a perversion of
the phrase's original intention by Atwood's fictional society.
In Vladimir Voinovich's 1986 novel Moscow 2042, the slogan was parodied in the context of "communism in one city". Every morning the radio announced: "Comrades, your needs for today are as follows: ...".
"To each according to his contribution" is a principle of distribution considered to be one of the defining features of socialism.
It refers to an arrangement whereby individual compensation is
representative of one's contribution to the social product (total output
of the economy) in terms of effort, labor and productivity. This is in contrast to the method of distribution and compensation in capitalism, an economic and political system in which property owners can receive unearned income by virtue of ownership irrespective of their contribution to the social product.
To each according to his contribution was a concept espoused by many members of the socialist and labor movement. The French socialist Saint-Simonists of the 1820s and 1830s used slogans such as," from each according to his ability, to each ability according to its work" or," From each according to his capacity, to each according to his works.” Other examples of this can be found from Ferdinand Lassalle's and Eugen Dühring's statements to Leon Trotsky's writings. Vladimir Lenin, inspired by Marx's writing on the subject in his Critique of the Gotha Programme, claimed the principle to be a fundamental element of socialism within Marxist theory.
The term means simply that each worker in a socialist society receives compensation and benefits according to the quantity and value of the labor
that he or she contributed. This translates into workers of great
productivity receiving more wages and benefits than workers of average
productivity, and substantially more than workers of lesser
productivity. An extension of this principle could also be made so that
the more difficult one's job is – whether this difficulty is derived
from greater training requirements, job intensity, safety hazards, etc. –
the more one is rewarded for the labor contributed. The purpose of the
principle, as Trotsky would later state,
is to promote productivity. This is done by creating incentives to work
harder, longer, and more productively. The principle is ultimately a
stowaway from capitalism that, according to Marx, will vanish as work
becomes more automated and enjoyable, and goods become available in
abundance.
Elaboration by Marx
The Critique of the Gotha Programme, while criticizing Ferdinand Lassalle's
ideas, Marx elaborates on the theory. According to Marx's analysis of
the Programme, Lassalle suggests that "the proceeds of labor belong
undiminished with equal right to all members of society". While agreeing
that the citizens of a workers' society should be rewarded according to
individual contributions, Marx claims that giving them the "full
product" of their labor is impossible as some of the proceeds will be
needed to maintain infrastructure and so forth. He then explains the nature of a communist society in its lower phase (socialist society),
which does not emerge from its own foundations "but, on the contrary,
.. from capitalist society; [and] thus in every respect, economically,
morally, and intellectually, still stamped with the birthmarks of the
old society from whose womb it emerges". And so, "accordingly, the
individual producer receives back from society – after the deductions
have been made – exactly what he gives to it". He explains this as:
What he has given to it is his
individual quantum of labor. For example, the social working day
consists of the sum of the individual hours of work; the individual
labor time of the individual producer is the part of the social working
day contributed by him, his share in it. He receives a certificate from society
that he has furnished such-and-such an amount of labor (after deducting
his labor for the common funds); and with this certificate, he draws
from the social stock of means of consumption as much as the same amount
of labor cost. The same amount of labor which he has given to society in one form, he receives back in another.
In the paragraph immediately following Marx continues to explain how
this system of exchange is related to the capitalist system of exchange:
Here, obviously, the same principle prevails as that which regulates the exchange of commodities, as far as this is exchange of equal values.
Content and form are changed, because under the altered circumstances
no one can give anything except his labor, and because, on the other
hand, nothing can pass to the ownership of individuals, except
individual means of consumption. But as far as the distribution of the
latter among the individual producers is concerned, the same principle
prevails as in the exchange of commodity equivalents: a given amount of labor in one form is exchanged for an equal amount of labor in another form.
Marx says that this is rational and necessary, and that once society
advances from the early phase of communist society and work becomes
life's prime want, distribution will occur differently. During the
completed phase of communism, the standard shall be "from each according to his ability, to each according to his needs".
Use by Bolsheviks and Marxist-Leninists
Lenin wrote The State and Revolution
to inform the public and to prevent Marxism from becoming tainted by
"opportunists" and "reformists", as he called them. The work is very
important as it categorizes the "first phase of communist society" as
socialism, with the completed phase being communism proper. The pamphlet
also answers all questions and concerns of the Marxists of his time by
utilizing the classic works of Marxism.
When he is set to describe socialism and its economic features he turns to the authority of Marx, especially the Critique of the Gotha Programme.
Lenin claims that socialism will not be perfect since, as Marx said, it
has emerged from the womb of capitalism and which is in every respect
stamped with the birthmarks of the old society. This society, socialism,
will be unable to provide people with total equality, precisely because
it is still marked by capitalism. He also explains the difference
between the old society and the new as:
The
means of production are no longer the private property of individuals.
The means of production belong to the whole of society. Every member of
society, performing a certain part of the socially-necessary work,
receives a certificate from society to the effect that he has done a
certain amount of work. And with this certificate he receives from the
public store of consumer goods a corresponding quantity of products.
After a deduction is made of the amount of labor which goes to the
public fund, every worker, therefore, receives from society as much as he has given to it.
Lenin states that such a society is indeed socialism as it realizes the two principles of socialism "he who does not work, neither shall he eat" and "an equal amount of products for an equal amount of labor".
Stalin's most famous use of the concept is in his 1936 Soviet Constitution. He writes that "The principle applied in the U.S.S.R. is that of socialism:From each according to his ability, to each according to his work."
Trotsky's mention is in his famous The Revolution Betrayed. He says that "Capitalism
prepared the conditions and forces for a social revolution: technique,
science and the proletariat. The communist structure cannot, however,
immediately replace the bourgeois society. The material and cultural
inheritance from the past is wholly inadequate for that." He goes on to defend his position by saying that "in
its first steps the workers’ state cannot yet permit everyone to work
"according to his abilities" – that is, as much as he can and wishes to –
nor can it reward everyone "according to his needs", regardless of the work he does." And he presents the principle as the method that socialism will use by saying: "In order to increase the productive forces, it is necessary to resort to the customary norms of wage payment – that is, tothe distribution of life's goods in proportion to the quantity and quality of individual labor."
The history of scientific method considers changes in the methodology of scientific inquiry, as distinct from the history of science itself. The development of rules for scientific reasoning
has not been straightforward; scientific method has been the subject
of intense and recurring debate throughout the history of science, and
eminent natural philosophers and scientists have argued for the primacy
of one or another approach to establishing scientific knowledge. Despite
the disagreements about approaches, scientific method has advanced in
definite steps. Rationalist explanations of nature, including atomism, appeared both in ancient Greece in the thought of Leucippus and Democritus, and in ancient India, in the Nyaya, Vaisesika and Buddhist schools, while Charvaka materialism rejected inference as a source of knowledge in favour of an empiricism that was always subject to doubt. Aristotle
pioneered scientific method in ancient Greece alongside his empirical
biology and his work on logic, rejecting a purely deductive framework in
favour of generalisations made from observations of nature.
Some of the most important debates in the history of scientific method center on: rationalism, especially as advocated by René Descartes; inductivism, which rose to particular prominence with Isaac Newton and his followers; and hypothetico-deductivism, which came to the fore in the early 19th century. In the late 19th and early 20th centuries, a debate over realism vs. antirealism
was central to discussions of scientific method as powerful scientific
theories extended beyond the realm of the observable, while in the
mid-20th century some prominent philosophers argued against any
universal rules of science at all.
There are few explicit discussions of scientific methodologies in
surviving records from early cultures. The most that can be inferred
about the approaches to undertaking science in this period stems from
descriptions of early investigations into nature, in the surviving
records. An Egyptian medical textbook, the Edwin Smith papyrus, (c. 1600 BCE), applies the following components: examination, diagnosis, treatment and prognosis, to the treatment of disease, which display strong parallels to the basic empirical method of science and according to G. E. R. Lloyd played a significant role in the development of this methodology. The Ebers papyrus (c. 1550 BCE) also contains evidence of traditional empiricism.
By the middle of the 1st millennium BCE in Mesopotamia, Babylonian astronomy
had evolved into the earliest example of a scientific astronomy, as it
was "the first and highly successful attempt at giving a refined
mathematical description of astronomical phenomena." According to the
historian Asger Aaboe, "all subsequent varieties of scientific astronomy, in the Hellenistic world, in India, in the Islamic world, and in the West – if not indeed all subsequent endeavour in the exact sciences – depend upon Babylonian astronomy in decisive and fundamental ways."
The early Babylonians and Egyptians developed much technical knowledge, crafts, and mathematics used in practical tasks of divination, as well as a knowledge of medicine, and made lists of various kinds. While the Babylonians in particular had engaged in the earliest forms of an empirical
mathematical science, with their early attempts at mathematically
describing natural phenomena, they generally lacked underlying rational
theories of nature.
Greek-speaking
ancient philosophers engaged in the earliest known forms of what is
today recognized as a rational theoretical science,
with the move towards a more rational understanding of nature which
began at least since the Archaic Period (650 – 480 BCE) with the
Presocratic school. Thales
was the first known philosopher to use natural explanations,
proclaiming that every event had a natural cause, even though he is
known for saying "all things are full of gods" and sacrificed an ox when
he discovered his theorem. Leucippus, went on to develop the theory of atomism – the idea that everything is composed entirely of various imperishable, indivisible elements called atoms. This was elaborated in great detail by Democritus.
Similar atomist ideas emerged independently among ancient Indian philosophers of the Nyaya, Vaisesika and Buddhist schools. In particular, like the Nyaya, Vaisesika, and Buddhist schools, the Cārvāka
epistemology was materialist, and skeptical enough to admit perception
as the basis for unconditionally true knowledge, while cautioning that
if one could only infer a truth, then one must also harbor a doubt about
that truth; an inferred truth could not be unconditional.
Towards the middle of the 5th century BCE, some of the components
of a scientific tradition were already heavily established, even before
Plato, who was an important contributor to this emerging tradition,
thanks to the development of deductive reasoning, as propounded by his
student, Aristotle. In Protagoras (318d-f), Plato
mentioned the teaching of arithmetic, astronomy and geometry in
schools. The philosophical ideas of this time were mostly freed from the
constraints of everyday phenomena and common sense. This denial of reality as we experience it reached an extreme in Parmenides who argued that the world is one and that change and subdivision do not exist.
In the 3rd and 4th centuries BCE, the Greek physicians Herophilos (335–280 BCE) and Erasistratus of Chios
employed experiments to further their medical research; Erasistratus at
one time repeatedly weighing a caged bird, and noting its weight loss
between feeding times.
Aristotle
Aristotle's philosophy involved both inductive and deductive reasoning.
Aristotle's inductive-deductive method used inductions from
observations to infer general principles, deductions from those
principles to check against further observations, and more cycles of
induction and deduction to continue the advance of knowledge.
The Organon (Greek: Ὄργανον, meaning "instrument, tool, organ") is the standard collection of Aristotle's six works on logic. The name Organon was given by Aristotle's followers, the Peripatetics.
The order of the works is not chronological (the chronology is now difficult to determine) but was deliberately chosen by Theophrastus to constitute a well-structured system. Indeed, parts of them seem to be a scheme of a lecture on logic. The arrangement of the works was made by Andronicus of Rhodes around 40 BCE.
The Organon comprises the following six works:
The Categories (Greek: Κατηγορίαι, Latin: Categoriae)
introduces Aristotle's 10-fold classification of that which exists:
substance, quantity, quality, relation, place, time, situation,
condition, action, and passion.
On Interpretation (Greek: Περὶ Ἑρμηνείας, Latin: De Interpretatione) introduces Aristotle's conception of proposition and judgment, and the various relations between affirmative, negative, universal, and particular propositions. Aristotle discusses the square of opposition or square of Apuleius in Chapter 7 and its appendix Chapter 8. Chapter 9 deals with the problem of future contingents.
The Prior Analytics (Greek: Ἀναλυτικὰ Πρότερα, Latin: Analytica Priora) introduces Aristotle's syllogistic method (see term logic), argues for its correctness, and discusses inductive inference.
The Topics (Greek: Τοπικά, Latin: Topica)
treats of issues in constructing valid arguments, and of inference that
is probable, rather than certain. It is in this treatise that
Aristotle mentions the predicables, later discussed by Porphyry and by the scholastic logicians.
The Sophistical Refutations (Greek: Περὶ Σοφιστικῶν Ἐλέγχων, Latin: De Sophisticis Elenchis) gives a treatment of logical fallacies, and provides a key link to Aristotle's work on rhetoric.
Aristotle's Metaphysics has some points of overlap with the works making up the Organon
but is not traditionally considered part of it; additionally there are
works on logic attributed, with varying degrees of plausibility, to
Aristotle that were not known to the Peripatetics.
Aristotle introduced what may be called a scientific method. His demonstration method is found in Posterior Analytics. He provided another of the ingredients of scientific tradition: empiricism.
For Aristotle, universal truths can be known from particular things via
induction. To some extent then, Aristotle reconciles abstract thought
with observation, although it would be a mistake to imply that
Aristotelian science is empirical in form. Indeed, Aristotle did not
accept that knowledge acquired by induction could rightly be counted as
scientific knowledge. Nevertheless, induction was for him a necessary
preliminary to the main business of scientific enquiry, providing the
primary premises required for scientific demonstrations.
Aristotle largely ignored inductive reasoning in his treatment of
scientific enquiry. To make it clear why this is so, consider this
statement in the Posterior Analytics:
We suppose ourselves to possess unqualified scientific
knowledge of a thing, as opposed to knowing it in the accidental way in
which the sophist knows, when we think that we know the cause on which
the fact depends, as the cause of that fact and of no other, and,
further, that the fact could not be other than it is.
It was therefore the work of the philosopher to demonstrate universal truths and to discover their causes.
While induction was sufficient for discovering universals by
generalization, it did not succeed in identifying causes. For this task
Aristotle used the tool of deductive reasoning in the form of syllogisms. Using the syllogism, scientists could infer new universal truths from those already established.
Aristotle developed a complete normative approach to scientific
inquiry involving the syllogism, which he discusses at length in his Posterior Analytics.
A difficulty with this scheme lay in showing that derived truths have
solid primary premises. Aristotle would not allow that demonstrations
could be circular (supporting the conclusion by the premises, and the
premises by the conclusion). Nor would he allow an infinite number of
middle terms between the primary premises and the conclusion. This leads
to the question of how the primary premises are found or developed, and
as mentioned above, Aristotle allowed that induction would be required
for this task.
Towards the end of the Posterior Analytics, Aristotle discusses knowledge imparted by induction.
Thus it is clear that we must get to know the primary
premises by induction; for the method by which even sense-perception
implants the universal is inductive. [...] it follows that there will be
no scientific knowledge of the primary premises, and since except
intuition nothing can be truer than scientific knowledge, it will be
intuition that apprehends the primary premises. [...] If, therefore, it
is the only other kind of true thinking except scientific knowing, intuition will be the originative source of scientific knowledge.
The account leaves room for doubt regarding the nature and extent of
Aristotle's empiricism. In particular, it seems that Aristotle considers
sense-perception only as a vehicle for knowledge through intuition. He
restricted his investigations in natural history to their natural
settings, such as at the Pyrrha lagoon, now called Kalloni, at Lesbos. Aristotle and Theophrastus together formulated the new science of biology, inductively, case by case, for two years before Aristotle was called to tutor Alexander.
Aristotle performed no modern-style experiments in the form in which
they appear in today's physics and chemistry laboratories.
Induction is not afforded the status of scientific reasoning, and so it
is left to intuition to provide a solid foundation for Aristotle's
science. With that said, Aristotle brings us somewhat closer an
empirical science than his predecessors.
Epicurus
In his work Kαvώv ('canon', a straight edge or ruler, thus any type of measure or standard, referred to as 'canonic'), Epicurus laid out his first rule for inquiry in physics: 'that the first concepts be seen, and that they not require demonstration '.
His second rule for inquiry was that prior to an investigation, we are to have self-evident concepts,
so that we might infer [ἔχωμεν οἷς σημειωσόμεθα] both what is expected
[τò προσμένον], and also what is non-apparent [τò ἄδηλον].
Epicurus applies his method of inference (the use of observations as signs, Asmis' summary, p. 333: the method of using the phenomena as signs (σημεῖα) of what is unobserved) immediately to the atomic theory of Democritus. In Aristotle's Prior Analytics, Aristotle himself employs the use of signs. But Epicurus presented his 'canonic' as rival to Aristotle's logic. See: Lucretius (c. 99 BCE – c. 55 BCE) De rerum natura (On the nature of things) a didactic poem explaining Epicurus' philosophy and physics.
Emergence of inductive experimental method
During the Middle Ages
issues of what is now termed science began to be addressed. There was
greater emphasis on combining theory with practice in the Islamic world
than there had been in Classical times, and it was common for those
studying the sciences to be artisans as well, something that had been
"considered an aberration in the ancient world." Islamic experts in the
sciences were often expert instrument makers who enhanced their powers
of observation and calculation with them. Starting in the early ninth century, early Muslim scientists such al-Kindi (801–873) and the authors writing under the name of Jābir ibn Hayyān (writings dated to c. 850–950) started to put a greater emphasis on the use of experiment as a source of knowledge. Several scientific methods thus emerged from the medieval Muslim world by the early 11th century, all of which emphasized experimentation as well as quantification to varying degrees.
Ibn al-Haytham
"How
does light travel through transparent bodies? Light travels through
transparent bodies in straight lines only.... We have explained this
exhaustively in our Book of Optics." —Alhazen
Experimental evidence supported most of the propositions in his Book of Optics
and grounded his theories of vision, light and colour, as well as his
research in catoptrics and dioptrics. His legacy was elaborated through
the 'reforming' of his Optics by Kamal al-Din al-Farisi (d. c. 1320) in the latter's Kitab Tanqih al-Manazir (The Revision of [Ibn al-Haytham's] Optics).
Alhazen viewed his scientific studies as a search for truth:
"Truth is sought for its own sake. And those who are engaged upon the
quest for anything for its own sake are not interested in other things.
Finding the truth is difficult, and the road to it is rough. ...
Alhazen's work included the conjecture that "Light travels
through transparent bodies in straight lines only", which he was able to
corroborate only after years of effort. He stated, "[This] is clearly
observed in the lights which enter into dark rooms through holes. ...
the entering light will be clearly observable in the dust which fills
the air." He also demonstrated the conjecture by placing a straight stick or a taut thread next to the light beam.
Ibn al-Haytham also employed scientific skepticism and emphasized the role of empiricism. He also explained the role of induction in syllogism, and criticized Aristotle
for his lack of contribution to the method of induction, which Ibn
al-Haytham regarded as superior to syllogism, and he considered
induction to be the basic requirement for true scientific research.
Something like Occam's razor is also present in the Book of Optics.
For example, after demonstrating that light is generated by luminous
objects and emitted or reflected into the eyes, he states that therefore
"the extramission of [visual] rays is superfluous and useless." He may also have been the first scientist to adopt a form of positivism
in his approach. He wrote that "we do not go beyond experience, and we
cannot be content to use pure concepts in investigating natural
phenomena", and that the understanding of these cannot be acquired
without mathematics. After assuming that light is a material substance,
he does not further discuss its nature but confines his investigations
to the diffusion and propagation of light. The only properties of light
he takes into account are those treatable by geometry and verifiable by
experiment.
Al-Biruni
The Persian scientist Abū Rayhān al-Bīrūnī introduced early scientific methods for several different fields of inquiry during the 1020s and 1030s. For example, in his treatise on mineralogy, Kitab al-Jawahir (Book of Precious Stones), al-Biruni is "the most exact of experimental scientists", while in the introduction to his study of India,
he declares that "to execute our project, it has not been possible to
follow the geometric method" and thus became one of the pioneers of comparative sociology in insisting on field experience and information. He also developed an early experimental method for mechanics.
Al-Biruni's methods resembled the modern scientific method,
particularly in his emphasis on repeated experimentation. Biruni was
concerned with how to conceptualize and prevent both systematic errors
and observational biases, such as "errors caused by the use of small
instruments and errors made by human observers." He argued that if
instruments produce errors because of their imperfections or
idiosyncratic qualities, then multiple observations must be taken, analyzed qualitatively, and on this basis, arrive at a "common-sense single value for the constant sought", whether an arithmetic mean or a "reliable estimate." In his scientific method, "universals came out of practical, experimental work" and "theories are formulated after discoveries", as with inductivism.
Ibn Sina (Avicenna)
In the On Demonstration section of The Book of Healing (1027), the Persian philosopher and scientist Avicenna (Ibn Sina) discussed philosophy of science and described an early scientific method of inquiry. He discussed Aristotle's Posterior Analytics
and significantly diverged from it on several points. Avicenna
discussed the issue of a proper procedure for scientific inquiry and the
question of "How does one acquire the first principles of a science?"
He asked how a scientist might find "the initial axioms or hypotheses of a deductive
science without inferring them from some more basic premises?" He
explained that the ideal situation is when one grasps that a "relation
holds between the terms, which would allow for absolute, universal
certainty." Avicenna added two further methods for finding a first principle: the ancient Aristotelian method of induction (istiqra), and the more recent method of examination and experimentation (tajriba).
Avicenna criticized Aristotelian induction, arguing that "it does not
lead to the absolute, universal, and certain premises that it purports
to provide." In its place, he advocated "a method of experimentation as a
means for scientific inquiry."
Earlier, in The Canon of Medicine (1025), Avicenna was also the first to describe what is essentially methods of agreement, difference and concomitant variation which are critical to inductive logic and the scientific method.
However, unlike his contemporary al-Biruni's scientific method, in
which "universals came out of practical, experimental work" and
"theories are formulated after discoveries", Avicenna developed a
scientific procedure in which "general and universal questions came
first and led to experimental work." Due to the differences between their methods, al-Biruni referred to himself as a mathematical scientist and to Avicenna as a philosopher, during a debate between the two scholars.
Robert Grosseteste
During the European Renaissance of the 12th century, ideas on scientific methodology, including Aristotle's empiricism and the experimental approaches of Alhazen and Avicenna, were introduced to medieval Europe via Latin translations of Arabic and Greek texts and commentaries. Robert Grosseteste's commentary on the Posterior Analytics places Grosseteste among the first scholastic thinkers in Europe to understand Aristotle's
vision of the dual nature of scientific reasoning. Concluding from
particular observations into a universal law, and then back again, from
universal laws to prediction of particulars. Grosseteste called this
"resolution and composition". Further, Grosseteste said that both paths
should be verified through experimentation to verify the principles.
Roger Bacon
Roger Bacon was inspired by the writings of Grosseteste. In his account of a method, Bacon described a repeating cycle of observation, hypothesis, experimentation, and the need for independent verification.
He recorded the way he had conducted his experiments in precise detail,
perhaps with the idea that others could reproduce and independently
test his results.
About 1256 he joined the Franciscan Order and became subject to the Franciscan statute forbidding Friars from publishing books or pamphlets without specific approval. After the accession of Pope Clement IV
in 1265, the Pope granted Bacon a special commission to write to him on
scientific matters. In eighteen months he completed three large
treatises, the Opus Majus, Opus Minus, and Opus Tertium which he sent to the Pope. William Whewell has called Opus Majus at once the Encyclopaedia and Organon of the 13th century.
Part I (pp. 1–22) treats of the four causes of error: authority,
custom, the opinion of the unskilled many, and the concealment of real
ignorance by a pretense of knowledge.
Part VI (pp. 445–477) treats of experimental science, domina omnium scientiarum.
There are two methods of knowledge: the one by argument, the other by
experience. Mere argument is never sufficient; it may decide a question,
but gives no satisfaction or certainty to the mind, which can only be
convinced by immediate inspection or intuition, which is what experience
gives.
Experimental science, which in the Opus Tertium (p. 46) is
distinguished from the speculative sciences and the operative arts, is
said to have three great prerogatives over all sciences:
It verifies their conclusions by direct experiment;
It discovers truths which they could never reach;
It investigates the secrets of nature, and opens to us a knowledge of past and future.
Roger Bacon illustrated his method by an investigation into the nature and cause of the rainbow, as a specimen of inductive research.
Renaissance humanism and medicine
Aristotle's
ideas became a framework for critical debate beginning with absorption
of the Aristotelian texts into the university curriculum in the first
half of the 13th century.
Contributing to this was the success of medieval theologians in
reconciling Aristotelian philosophy with Christian theology. Within the
sciences, medieval philosophers were not afraid of disagreeing with
Aristotle on many specific issues, although their disagreements were
stated within the language of Aristotelian philosophy. All medieval
natural philosophers were Aristotelians, but "Aristotelianism" had
become a somewhat broad and flexible concept. With the end of Middle
Ages, the Renaissance
rejection of medieval traditions coupled with an extreme reverence for
classical sources led to a recovery of other ancient philosophical
traditions, especially the teachings of Plato.
By the 17th century, those who clung dogmatically to Aristotle's
teachings were faced with several competing approaches to nature.
The discovery of the Americas at the close of the 15th century showed
the scholars of Europe that new discoveries could be found outside of
the authoritative works of Aristotle, Pliny, Galen, and other ancient
writers.
Galen of Pergamon (129 – c. 200 AD) had studied with four schools in antiquity — Platonists, Aristotelians, Stoics, and Epicureans, and at Alexandria, the center of medicine at the time. In his Methodus Medendi,
Galen had synthesized the empirical and dogmatic schools of medicine
into his own method, which was preserved by Arab scholars. After the
translations from Arabic were critically scrutinized, a backlash
occurred and demand arose in Europe for translations of Galen's medical
text from the original Greek. Galen's method became very popular in
Europe. Thomas Linacre, the teacher of Erasmus, thereupon translated Methodus Medendi from Greek into Latin for a larger audience in 1519.
Limbrick 1988 notes that 630 editions, translations, and commentaries
on Galen were produced in Europe in the 16th century, eventually
eclipsing Arabic medicine there, and peaking in 1560, at the time of the
scientific revolution.
By the late 15th century, the physician-scholar Niccolò Leoniceno was finding errors in Pliny's Natural History. As a physician, Leoniceno was concerned about these botanical errors propagating to the materia medica on which medicines were based. To counter this, a botanical garden was established at Orto botanico di Padova,
University of Padua (in use for teaching by 1546), in order that
medical students might have empirical access to the plants of a
pharmacopia. Other Renaissance teaching gardens were established,
notably by the physician Leonhart Fuchs, one of the founders of botany.
The first published work devoted to the concept of method is Jodocus Willichius, De methodo omnium artium et disciplinarum informanda opusculum (1550).
Skepticism as a basis for understanding
In 1562 Outlines of Pyrrhonism by the ancient Pyrrhonist philosopher Sextus Empiricus
(c. 160-210 AD) was published in a Latin translation (from Greek),
quickly placing the arguments of classical skepticism in the European
mainstream. Skepticism either denies or strongly doubts (depending on
the school) the possibility of certain knowledge. Descartes' famous "Cogito"
argument is an attempt to overcome skepticism and reestablish a
foundation for certainty but other thinkers responded by revising what
the search for knowledge, particularly physical knowledge, might be.
The first of these, philosopher and physician Francisco Sanches, was led by his medical training at Rome, 1571–73, to search for a true method of knowing (modus sciendi), as nothing clear can be known by the methods of Aristotle and his followers — for example, 1) syllogism fails upon circular reasoning; 2) Aristotle's modal logic was not stated clearly enough for use in medieval times, and remains a research problem to this day. Following the physician Galen's method of medicine, Sanches lists the methods of judgement and experience, which are faulty in the wrong hands, and we are left with the bleak statement That Nothing is Known (1581, in Latin Quod Nihil Scitur).
This challenge was taken up by René Descartes in the next generation
(1637), but at the least, Sanches warns us that we ought to refrain from
the methods, summaries, and commentaries on Aristotle, if we seek
scientific knowledge. In this, he is echoed by Francis Bacon who was
influenced by another prominent exponent of skepticism, Montaigne; Sanches cites the humanist Juan Luis Vives
who sought a better educational system, as well as a statement of human
rights as a pathway for improvement of the lot of the poor.
"Sanches develops his scepticism by means of an intellectual
critique of Aristotelianism, rather than by an appeal to the history of
human stupidity and the variety and contrariety of previous theories." —Popkin 1979, p. 37, as cited by Sanches, Limbrick & Thomson 1988, pp. 24–5
"To work, then; and if you know
something, then teach me; I shall be extremely grateful to you. In the
meantime, as I prepare to examine Things, I shall raise the question anything is known, and if so, how, in the introductory passages of another book, a book in which I will expound, as far as human frailty allows, the method of knowing. Farewell.
WHAT IS TAUGHT HAS NO MORE STRENGTH THAN IT DERIVES FROM HIM WHO IS TAUGHT.
"If a man will begin with
certainties, he shall end in doubts; but if he will be content to begin
with doubts, he shall end in certainties." —Francis Bacon (1605) The Advancement of Learning, Book 1, v, 8
Francis Bacon (1561–1626) entered Trinity College, Cambridge
in April 1573, where he applied himself diligently to the several
sciences as then taught, and came to the conclusion that the methods
employed and the results attained were alike erroneous; he learned to
despise the current Aristotelian philosophy. He believed philosophy must
be taught its true purpose, and for this purpose a new method must be
devised. With this conception in his mind, Bacon left the university.
Bacon attempted to describe a rational procedure for establishing
causation between phenomena based on induction. Bacon's induction was,
however, radically different than that employed by the Aristotelians. As
Bacon put it,
[A]nother form of induction must be devised than has
hitherto been employed, and it must be used for proving and discovering
not first principles (as they are called) only, but also the lesser
axioms, and the middle, and indeed all. For the induction which proceeds
by simple enumeration is childish. —Novum Organum section CV
Bacon's method relied on experimental histories to eliminate alternative theories. Bacon explains how his method is applied in his Novum Organum
(published 1620). In an example he gives on the examination of the
nature of heat, Bacon creates two tables, the first of which he names
"Table of Essence and Presence", enumerating the many various
circumstances under which we find heat. In the other table, labelled
"Table of Deviation, or of Absence in Proximity", he lists circumstances
which bear resemblance to those of the first table except for the
absence of heat. From an analysis of what he calls the natures (light emitting, heavy, colored, etc.) of the items in these lists we are brought to conclusions about the form nature,
or cause, of heat. Those natures which are always present in the first
table, but never in the second are deemed to be the cause of heat.
The role experimentation played in this process was twofold. The
most laborious job of the scientist would be to gather the facts, or
'histories', required to create the tables of presence and absence. Such
histories would document a mixture of common knowledge and experimental
results. Secondly, experiments of light, or, as we might say, crucial experiments would be needed to resolve any remaining ambiguities over causes.
Bacon showed an uncompromising commitment to experimentation.
Despite this, he did not make any great scientific discoveries during
his lifetime. This may be because he was not the most able experimenter. It may also be because hypothesising plays only a small role in Bacon's method compared to modern science.
Hypotheses, in Bacon's method, are supposed to emerge during the
process of investigation, with the help of mathematics and logic. Bacon
gave a substantial but secondary role to mathematics "which ought only to give definiteness to natural philosophy, not to generate or give it birth" (Novum Organum XCVI).
An over-emphasis on axiomatic reasoning had rendered previous
non-empirical philosophy impotent, in Bacon's view, which was expressed
in his Novum Organum:
XIX. There are and can be only two ways of searching into and
discovering truth. The one flies from the senses and particulars to the
most general axioms, and from these principles, the truth of which it
takes for settled and immoveable, proceeds to judgment and to the
discovery of middle axioms. And this way is now in fashion. The other
derives axioms from the senses and particulars, rising by a gradual and
unbroken ascent, so that it arrives at the most general axioms last of
all. This is the true way, but as yet untried.
Lastly, we have three that raise the former discoveries by
experiments into greater observations, axioms, and aphorisms. These we
call interpreters of nature.
In 1619, René Descartes began writing his first major treatise on proper scientific and philosophical thinking, the unfinished Rules for the Direction of the Mind.
His aim was to create a complete science that he hoped would overthrow
the Aristotelian system and establish himself as the sole architect of a new system of guiding principles for scientific research.
This work was continued and clarified in his 1637 treatise, Discourse on Method, and in his 1641 Meditations.
Descartes describes the intriguing and disciplined thought experiments
he used to arrive at the idea we instantly associate with him: I think therefore I am.
From this foundational thought, Descartes finds proof of the
existence of a God who, possessing all possible perfections, will not
deceive him provided he resolves "[...] never to accept anything for
true which I did not clearly know to be such; that is to say, carefully
to avoid precipitancy and prejudice, and to comprise nothing more in my
judgment than what was presented to my mind so clearly and distinctly as
to exclude all ground of methodic doubt."
This rule allowed Descartes to progress beyond his own thoughts
and judge that there exist extended bodies outside of his own thoughts.
Descartes published seven sets of objections to the Meditations from various sources
along with his replies to them. Despite his apparent departure from the
Aristotelian system, a number of his critics felt that Descartes had
done little more than replace the primary premises of Aristotle with
those of his own. Descartes says as much himself in a letter written in
1647 to the translator of Principles of Philosophy,
a perfect knowledge [...] must necessarily be deduced
from first causes [...] we must try to deduce from these principles
knowledge of the things which depend on them, that there be nothing in
the whole chain of deductions deriving from them that is not perfectly
manifest.
And again, some years earlier, speaking of Galileo's physics in a letter to his friend and critic Mersenne from 1638,
without having considered the first causes of nature,
[Galileo] has merely looked for the explanations of a few particular
effects, and he has thereby built without foundations.
Whereas Aristotle purported to arrive at his first principles by
induction, Descartes believed he could obtain them using reason only. In
this sense, he was a Platonist, as he believed in the innate ideas, as
opposed to Aristotle's blank slate (tabula rasa), and stated that the seeds of science are inside us.
Unlike Bacon, Descartes successfully applied his own ideas in
practice. He made significant contributions to science, in particular in
aberration-corrected optics. His work in analytic geometry was a necessary precedent to differential calculus and instrumental in bringing mathematical analysis to bear on scientific matters.
During the period of religious conservatism brought about by the Reformation and Counter-Reformation, Galileo Galilei
unveiled his new science of motion. Neither the contents of Galileo's
science, nor the methods of study he selected were in keeping with
Aristotelian teachings. Whereas Aristotle thought that a science should
be demonstrated from first principles, Galileo had used experiments as a
research tool. Galileo nevertheless presented his treatise in the form
of mathematical demonstrations without reference to experimental
results. It is important to understand that this in itself was a bold
and innovative step in terms of scientific method. The usefulness of
mathematics in obtaining scientific results was far from obvious. This is because mathematics did not lend itself to the primary pursuit of Aristotelian science: the discovery of causes.
Whether it is because Galileo was realistic about the
acceptability of presenting experimental results as evidence or because
he himself had doubts about the epistemological status of experimental findings is not known. Nevertheless, it is not in his Latin
treatise on motion that we find reference to experiments, but in his
supplementary dialogues written in the Italian vernacular. In these
dialogues experimental results are given, although Galileo may have
found them inadequate for persuading his audience. Thought experiments
showing logical contradictions in Aristotelian thinking, presented in
the skilled rhetoric of Galileo's dialogue were further enticements for
the reader.
Modern
replica of Galileo's inclined plane experiment: The distance covered by
a uniformly accelerated body is proportional to the square of the time
elapsed.
As an example, in the dramatic dialogue titled Third Day from his Two New Sciences,
Galileo has the characters of the dialogue discuss an experiment
involving two free falling objects of differing weight. An outline of
the Aristotelian view is offered by the character Simplicio. For this
experiment he expects that "a body which is ten times as heavy as
another will move ten times as rapidly as the other". The character
Salviati, representing Galileo's persona in the dialogue, replies by
voicing his doubt that Aristotle ever attempted the experiment. Salviati
then asks the two other characters of the dialogue to consider a
thought experiment whereby two stones of differing weights are tied
together before being released. Following Aristotle, Salviati reasons
that "the more rapid one will be partly retarded by the slower, and the
slower will be somewhat hastened by the swifter". But this leads to a
contradiction, since the two stones together make a heavier object than
either stone apart, the heavier object should in fact fall with a speed
greater than that of either stone. From this contradiction, Salviati
concludes that Aristotle must, in fact, be wrong and the objects will
fall at the same speed regardless of their weight, a conclusion that is
borne out by experiment.
In his 1991 survey of developments in the modern accumulation of knowledge such as this, Charles Van Doren
considers that the Copernican Revolution really is the Galilean
Cartesian (René Descartes) or simply the Galilean revolution on account
of the courage and depth of change brought about by the work of Galileo.
Both Bacon and Descartes wanted to provide a firm foundation for
scientific thought that avoided the deceptions of the mind and senses.
Bacon envisaged that foundation as essentially empirical, whereas
Descartes provides a metaphysical foundation for knowledge. If there
were any doubts about the direction in which scientific method would
develop, they were set to rest by the success of Isaac Newton. Implicitly rejecting Descartes' emphasis on rationalism in favor of Bacon's empirical approach, he outlines his four "rules of reasoning" in the Principia,
We are to admit no more causes of natural things than such as are both true and sufficient to explain their appearances.
Therefore to the same natural effects we must, as far as possible, assign the same causes.
The qualities of bodies, which admit neither intension nor remission
of degrees, and which are found to belong to all bodies within the
reach of our experiments, are to be esteemed the universal qualities of
all bodies whatsoever.
In experimental philosophy we are to look upon propositions
collected by general induction from phænomena as accurately or very
nearly true, notwithstanding any contrary hypotheses that may be
imagined, until such time as other phænomena occur, by which they may
either be made more accurate, or liable to exceptions.
To explain all nature is too difficult a task for any one
man or even for any one age. 'Tis much better to do a little with
certainty, and leave the rest for others that come after you, than to
explain all things.
Newton's work became a model that other sciences sought to emulate,
and his inductive approach formed the basis for much of natural
philosophy through the 18th and early 19th centuries. Some methods of
reasoning were later systematized by Mill's Methods
(or Mill's canon), which are five explicit statements of what can be
discarded and what can be kept while building a hypothesis. George Boole and William Stanley Jevons also wrote on the principles of reasoning.
Integrating deductive and inductive method
Attempts to systematize a scientific method were confronted in the mid-18th century by the problem of induction, a positivist logic formulation which, in short, asserts that nothing can be known with certainty except what is actually observed. David Hume
took empiricism to the skeptical extreme; among his positions was that
there is no logical necessity that the future should resemble the past,
thus we are unable to justify inductive reasoning itself by appealing to
its past success. Hume's arguments, of course, came on the heels of
many, many centuries of excessive speculation upon excessive speculation
not grounded in empirical observation and testing. Many of Hume's
radically skeptical arguments were argued against, but not resolutely
refuted, by Immanuel Kant's Critique of Pure Reason in the late 18th century.
Hume's arguments continue to hold a strong lingering influence and
certainly on the consciousness of the educated classes for the better
part of the 19th century when the argument at the time became the focus
on whether or not the inductive method was valid.
Hans Christian Ørsted, (Ørsted is the Danish spelling; Oersted in other languages) (1777–1851) was heavily influenced by Kant, in particular, Kant's Metaphysische Anfangsgründe der Naturwissenschaft (Metaphysical Foundations of Natural Science). The following sections on Ørsted encapsulate our current, common view of scientific method.
His work appeared in Danish, most accessibly in public lectures, which
he translated into German, French, English, and occasionally Latin. But
some of his views go beyond Kant:
Ørsted observed the deflection of a compass from a voltaic circuit in 1820
"In order to achieve completeness in our knowledge of nature, we
must start from two extremes, from experience and from the intellect
itself. ... The former method must conclude with natural laws, which it
has abstracted from experience, while the latter must begin with
principles, and gradually, as it develops more and more, it becomes ever
more detailed. Of course, I speak here about the method as manifested
in the process of the human intellect itself, not as found in textbooks,
where the laws of nature which have been abstracted from the consequent
experiences are placed first because they are required to explain the
experiences. When the empiricist in his regression towards general laws
of nature meets the metaphysician in his progression, science will reach
its perfection."
Ørsted's "First Introduction to General Physics" (1811) exemplified the steps of observation, hypothesis, deduction and experiment. In 1805, based on his researches on electromagnetism
Ørsted came to believe that electricity is propagated by undulatory
action (i.e., fluctuation). By 1820, he felt confident enough in his
beliefs that he resolved to demonstrate them in a public lecture, and in
fact observed a small magnetic effect from a galvanic circuit (i.e.,
voltaic circuit), without rehearsal;
In 1831 John Herschel (1792–1871) published A Preliminary Discourse on the study of Natural Philosophy,
setting out the principles of science. Measuring and comparing
observations was to be used to find generalisations in "empirical laws",
which described regularities in phenomena, then natural philosophers
were to work towards the higher aim of finding a universal "law of
nature" which explained the causes and effects producing such
regularities. An explanatory hypothesis was to be found by evaluating
true causes (Newton's "vera causae") derived from experience, for
example evidence of past climate change could be due to changes in the
shape of continents, or to changes in Earth's orbit. Possible causes
could be inferred by analogy to known causes of similar phenomena.
It was essential to evaluate the importance of a hypothesis; "our next
step in the verification of an induction must, therefore, consist in
extending its application to cases not originally contemplated; in
studiously varying the circumstances under which our causes act, with a
view to ascertain whether their effect is general; and in pushing the
application of our laws to extreme cases."
William Whewell (1794–1866) regarded his History of the Inductive Sciences, from the Earliest to the Present Time (1837) to be an introduction to the Philosophy of the Inductive Sciences
(1840) which analyzes the method exemplified in the formation of ideas.
Whewell attempts to follow Bacon's plan for discovery of an effectual
art of discovery. He named the hypothetico-deductive method (which Encyclopædia Britannica credits to Newton); Whewell also coined the term scientist. Whewell examines ideas and attempts to construct science by uniting ideas to facts. He analyses induction into three steps:
the selection of the fundamental idea, such as space, number, cause, or likeness
a more special modification of those ideas, such as a circle, a uniform force, etc.
the determination of magnitudes
Upon these follow special techniques applicable for quantity, such as the method of least squares, curves, means, and special methods depending on resemblance (such as pattern matching, the method of gradation, and the method of natural classification (such as cladistics).
But no art of discovery, such as Bacon anticipated, follows, for "invention, sagacity, genius" are needed at every step.
Whewell's sophisticated concept of science had similarities to that
shown by Herschel, and he considered that a good hypothesis should
connect fields that had previously been thought unrelated, a process he
called consilience. However, where Herschel held that the origin of new biological species
would be found in a natural rather than a miraculous process, Whewell
opposed this and considered that no natural cause had been shown for adaptation so an unknown divine cause was appropriate.
John Stuart Mill (1806–1873) was stimulated to publish A System of Logic (1843) upon reading Whewell's History of the Inductive Sciences. Mill may be regarded as the final exponent of the empirical school of philosophy begun by John Locke,
whose fundamental characteristic is the duty incumbent upon all
thinkers to investigate for themselves rather than to accept the
authority of others. Knowledge must be based on experience.
In the mid-19th century Claude Bernard was also influential, especially in bringing the scientific method to medicine. In his discourse on scientific method, An Introduction to the Study of Experimental Medicine
(1865), he described what makes a scientific theory good and what makes
a scientist a true discoverer. Unlike many scientific writers of his
time, Bernard wrote about his own experiments and thoughts, and used the
first person.
William Stanley Jevons' The Principles of Science: a treatise on logic and scientific method
(1873, 1877) Chapter XII "The Inductive or Inverse Method", Summary of
the Theory of Inductive Inference, states "Thus there are but three
steps in the process of induction :-
Framing some hypothesis as to the character of the general law.
Deducing some consequences of that law.
Observing whether the consequences agree with the particular tasks under consideration."
Jevons then frames those steps in terms of probability, which he then applied to economic laws. Ernest Nagel notes that Jevons and Whewell were not the first writers to argue for the centrality of the hypothetico-deductive method in the logic of science.
In the late 19th century, Charles Sanders Peirce
proposed a schema that would turn out to have considerable influence in
the further development of scientific method generally. Peirce's work
quickly accelerated the progress on several fronts. Firstly, speaking in
broader context in "How to Make Our Ideas Clear" (1878),
Peirce outlined an objectively verifiable method to test the truth of
putative knowledge on a way that goes beyond mere foundational
alternatives, focusing upon both Deduction and Induction.
He thus placed induction and deduction in a complementary rather than
competitive context (the latter of which had been the primary trend at
least since David Hume
a century before). Secondly, and of more direct importance to
scientific method, Peirce put forth the basic schema for
hypothesis-testing that continues to prevail today. Extracting the
theory of inquiry from its raw materials in classical logic, he refined
it in parallel with the early development of symbolic logic to address
the then-current problems in scientific reasoning. Peirce examined and
articulated the three fundamental modes of reasoning that play a role in
scientific inquiry today, the processes that are currently known as abductive, deductive, and inductive inference. Thirdly, he played a major role in the progress of symbolic logic itself – indeed this was his primary specialty.
Charles S. Peirce was also a pioneer in statistics.
Peirce held that science achieves statistical probabilities, not
certainties, and that chance, a veering from law, is very real. He
assigned probability to an argument's conclusion rather than to a
proposition, event, etc., as such. Most of his statistical writings
promote the frequency interpretation of probability (objective ratios of cases), and many of his writings express skepticism about (and criticize the use of) probability when such models are not based on objective randomization. Though Peirce was largely a frequentist, his possible world semantics introduced the "propensity" theory of probability. Peirce (sometimes with Jastrow) investigated the probability judgments of experimental subjects, pioneering decision analysis.
Karl Popper
(1902–1994) is generally credited with providing major improvements in
the understanding of the scientific method in the mid-to-late 20th
century. In 1934 Popper published The Logic of Scientific Discovery,
which repudiated the by then traditional observationalist-inductivist
account of the scientific method. He advocated empirical falsifiability as the criterion for distinguishing scientific work from non-science.
According to Popper, scientific theory should make predictions
(preferably predictions not made by a competing theory) which can be
tested and the theory rejected if these predictions are shown not to be
correct. Following Peirce and others, he argued that science would best
progress using deductive reasoning as its primary emphasis, known as critical rationalism.
His astute formulations of logical procedure helped to rein in the
excessive use of inductive speculation upon inductive speculation, and
also helped to strengthen the conceptual foundations for today's peer review procedures.
Ludwik Fleck, a Polish epidemiologist who was contemporary with Karl Popper but who influenced Kuhn and others with his Genesis and Development of a Scientific Fact (in German 1935, English 1979). Before Fleck, scientific fact was thought to spring fully formed (in the view of Max Jammer, for example), when a gestation period is now recognized to be essential before acceptance of a phenomenon as fact.
Critics of Popper, chiefly Thomas Kuhn, Paul Feyerabend and Imre Lakatos, rejected the idea that there exists a single method that applies to all science and could account for its progress. In 1962 Kuhn published the influential book The Structure of Scientific Revolutions
which suggested that scientists worked within a series of paradigms,
and argued there was little evidence of scientists actually following a
falsificationist methodology. Kuhn quoted Max Planck
who had said in his autobiography, "a new scientific truth does not
triumph by convincing its opponents and making them see the light, but
rather because its opponents eventually die, and a new generation grows
up that is familiar with it."
These debates clearly show that there is no universal agreement as to what constitutes the "scientific method". There remain, nonetheless, certain core principles that are the foundation of scientific inquiry today.
Mention of the topic
In Quod Nihil Scitur (1581), Francisco Sanches refers to another book title, De modo sciendi (on the method of knowing). This work appeared in Spanish as Método universal de las ciencias.
In 1833 Robert and William Chambers
published their 'Chambers's information for the people'. Under the
rubric 'Logic' we find a description of investigation that is familiar
as scientific method,
Investigation, or the art of inquiring into the nature of
causes and their operation, is a leading characteristic of reason [...]
Investigation implies three things – Observation, Hypothesis, and
Experiment [...] The first step in the process, it will be perceived, is
to observe...
In 1885, the words "Scientific method" appear together with a description of the method in Francis Ellingwood Abbot's 'Scientific Theism',
Now all the established truths which are formulated in
the multifarious propositions of science have been won by the use of
Scientific Method. This method consists in essentially three distinct
steps (1) observation and experiment, (2) hypothesis, (3) verification
by fresh observation and experiment.
The Eleventh Edition of Encyclopædia Britannica did not
include an article on scientific method; the Thirteenth Edition listed
scientific management, but not method. By the Fifteenth Edition, a
1-inch article in the Micropædia of Britannica was part of the
1975 printing, while a fuller treatment (extending across multiple
articles, and accessible mostly via the index volumes of Britannica) was
available in later printings.
Current issues
In the past few centuries, some statistical methods
have been developed, for reasoning in the face of uncertainty, as an
outgrowth of methods for eliminating error. This was an echo of the
program of Francis Bacon's Novum Organum of 1620. Bayesian inference acknowledges one's ability to alter one's beliefs in the face of evidence. This has been called belief revision, or defeasible reasoning:
the models in play during the phases of scientific method can be
reviewed, revisited and revised, in the light of further evidence. This
arose from the work of Frank P. Ramsey
(1903–1930), of John Maynard Keynes
(1883–1946), and earlier, of William Stanley Jevons (1835–1882) in economics.
Science and pseudoscience
The question of how science operates and therefore how to distinguish genuine science from pseudoscience has importance well beyond scientific circles or the academic community. In the judicial system and in public policy controversies, for example, a study's deviation from accepted scientific practice is grounds for rejecting it as junk science
or pseudoscience. However, the high public perception of science means
that pseudoscience is widespread. An advertisement in which an actor
wears a white coat and product ingredients are given Greek or Latin
sounding names is intended to give the impression of scientific
endorsement. Richard Feynman has likened pseudoscience to cargo cults
in which many of the external forms are followed, but the underlying
basis is missing: that is, fringe or alternative theories often present
themselves with a pseudoscientific appearance to gain acceptance.
