One of the five paintings of Extermination of Evil portrays Sendan Kendatsuba, one of the eight guardians of Buddhist law, banishing evil.
Evil, in a general sense, is the opposite or absence of good. It can be an extremely broad concept, although in everyday usage is often used more narrowly to talk about profound wickedness. It is generally seen as taking multiple possible forms, such as the form of personal moral evil commonly associated with the word, or impersonal natural evil (as in the case of natural disasters or illnesses), and in religious thought, the form of the demonic or supernatural/eternal.
Evil can denote profound immorality, but typically not without some basis in the understanding of the human condition, where strife and suffering (cf. Hinduism) are the true roots of evil. In certain religious contexts, evil has been described as a supernatural force. Definitions of evil vary, as does the analysis of its motives. Elements that are commonly associated with personal forms of evil involve unbalanced behavior including anger, revenge, hatred, psychological trauma, expediency, selfishness, ignorance, destruction and neglect.
Evil is also sometimes perceived as the dualistic antagonistic binary opposite to good, in which good should prevail and evil should be defeated. In cultures with Buddhist spiritual influence, both good and evil are perceived as part of an antagonistic duality that itself must be overcome through achieving Nirvana. The philosophical questions regarding good and evil are subsumed into three major areas of study: meta-ethics concerning the nature of good and evil, normative ethics concerning how we ought to behave, and applied ethics
concerning particular moral issues. While the term is applied to events
and conditions without agency, the forms of evil addressed in this
article presume an evildoer or doers.
While some religions focus on good vs. evil, other religions and
philosophies deny evil's existence and usefulness in describing people.
The root meaning of the word is of obscure origin though shown to be akin to modern GermanDas Übel (although evil is normally translated as Das Böse) with the basic idea of transgressing.
Chinese moral philosophy
As with Buddhism, in Confucianism or Taoism there is no direct analogue to the way good and evil are opposed although reference to demonic influence is common in Chinese folk religion.
Confucianism's primary concern is with correct social relationships and
the behavior appropriate to the learned or superior man. Thus evil would correspond to wrong behavior. Still less does it map into Taoism, in spite of the centrality of dualism in that system,
but the opposite of the cardinal virtues of Taoism, compassion,
moderation, and humility can be inferred to be the analogue of evil in
it.
1. By good, I understand that which we certainly know is useful to us. 2. By evil, on the contrary, I understand that which we certainly know hinders us from possessing anything that is good.
Spinoza assumes a quasi-mathematical
style and states these further propositions which he purports to prove
or demonstrate from the above definitions in part IV of his Ethics :
Proposition 8 "Knowledge of good or evil is nothing but affect of joy or sorrow in so far as we are conscious of it."
Proposition 30 "Nothing can be evil through that which it
possesses in common with our nature, but in so far as a thing is evil to
us it is contrary to us."
Proposition 64 "The knowledge of evil is inadequate knowledge."
Corollary "Hence it follows that if the human mind had none but adequate ideas, it would form no notion of evil."
Proposition 65 "According to the guidance of reason, of two
things which are good, we shall follow the greater good, and of two
evils, follow the less."
Proposition 68 "If men were born free, they would form no conception of good and evil so long as they were free."
Nietzsche
Friedrich Nietzsche, in a rejection of Judeo-Christian morality, addresses this in two works Beyond Good and Evil and On the Genealogy of Morals
where he essentially says that the natural, functional non-good has
been socially transformed into the religious concept of evil by the
slave mentality of the weak and oppressed masses who resent their
masters (the strong).
Psychology
Carl Jung
Carl Jung, in his book Answer to Job and elsewhere, depicted evil as the dark side of God. People tend to believe evil is something external to them, because they project their shadow onto others. Jung interpreted the story of Jesus as an account of God facing his own shadow.
Even though the book may have had a sudden birth, its gestation
period in Jung's unconscious was long. The subject of God, and what Jung
saw as the dark side of God, was a lifelong preoccupation. An emotional
and theoretical struggle with the core nature of deity is evident in
Jung's earliest fantasies and dreams, as well as in his complex
relationships with his father (a traditional minister), his mother (who
had a strong spiritual-mystical dimension), and the Christian church
itself. Jung's account of his childhood in his quasi-autobiography,
Memories, Dreams, Reflections (New York: Vintage, 1963), provides deep,
personal background about his early religious roots– and conflicts.
Philip Zimbardo
In 2007, Philip Zimbardo suggested that people may act in evil ways as a result of a collective identity. This hypothesis, based on his previous experience from the Stanford prison experiment, was published in the book The Lucifer Effect: Understanding How Good People Turn Evil.
Religion
Problem of evil and source
Most monotheistic religions posit that the singular God is all-powerful, all-knowing, and completely good. The problem of evil
asks how the apparent contradiction of these properties and the
observed existence of evil in the world might be resolved. Scholars
have examined the question of suffering caused by and in both humans and
animals, suffering caused by nature (like storms and disease). These
religions tend to attribute the source of evil to something other than God, such as demonic beings or human disobedience.
Polytheistic and non-theistic religions do not have such an
apparent contradiction, but many seek to explain or identify the source
of evil or suffering. These include concepts of evil as a necessary
balancing or enabling force, a consequence of past deeds (karma in Indian religions), or as an illusion, possibly produced by ignorance or failure to achieve enlightenment.
Non-religious atheism generally accepts evil acts as a feature of human actions arising from intelligent brains shaped by evolution, and suffering from nature as a result of complex natural systems simply following physical laws.
Abrahamic religions
Bahá'í Faith
The Bahá'í Faith
asserts that evil is non-existent and that it is a concept reflecting
lack of good, just as cold is the state of no heat, darkness is the
state of no light, forgetfulness the lacking of memory, ignorance the
lacking of knowledge. All of these are states of lacking and have no
real existence.
"Nevertheless a doubt occurs to the mind—that is, scorpions and
serpents are poisonous. Are they good or evil, for they are existing
beings? Yes, a scorpion is evil in relation to man; a serpent is evil in
relation to man; but in relation to themselves they are not evil, for
their poison is their weapon, and by their sting they defend
themselves."
Thus, evil is more of an intellectual concept than a true
reality. Since God is good, and upon creating creation he confirmed it
by saying it is Good (Genesis 1:31) evil cannot have a true reality.
Christianity
The devil, in opposition to the will of God, represents evil and tempts Christ, the personification of the character and will of God. Ary Scheffer, 1854.
Christian theology draws its concept of evil from the Old and New Testaments. The Christian Bible exercises "the dominant influence upon ideas about God and evil in the Western world."
In the Old Testament, evil is understood to be an opposition to God as
well as something unsuitable or inferior such as the leader of the fallen angelsSatan In the New Testament the Greek word poneros is used to indicate unsuitability, while kakos is used to refer to opposition to God in the human realm. Officially, the Catholic Church extracts its understanding of evil from its canonical antiquity and the Dominicantheologian, Thomas Aquinas, who in Summa Theologica defines evil as the absence or privation of good. French-American theologian Henri Blocher
describes evil, when viewed as a theological concept, as an
"unjustifiable reality. In common parlance, evil is 'something' that
occurs in the experience that ought not to be."
In Mormonism, mortal life is viewed as a test of faith, where one's choices are central to the Plan of Salvation. See Agency (LDS Church).
Evil is that which keeps one from discovering the nature of God. It is
believed that one must choose not to be evil to return to God.
Christian Science
believes that evil arises from a misunderstanding of the goodness of
nature, which is understood as being inherently perfect if viewed from
the correct (spiritual) perspective. Misunderstanding God's reality
leads to incorrect choices, which are termed evil. This has led to the
rejection of any separate power being the source of evil, or of God as
being the source of evil; instead, the appearance of evil is the result
of a mistaken concept of good. Christian Scientists argue that even the
most evil person does not pursue evil for its own sake, but from
the mistaken viewpoint that he or she will achieve some kind of good
thereby.
Islam
There is no concept of absolute evil in Islam, as a fundamental universal principle that is independent from and equal with good in a dualistic sense. Although the Quran mentions the biblical forbidden tree, it never refers to it as the 'tree of knowledge of good and evil'. Within Islam, it is considered essential to believe that all comes from God, whether it is perceived as good or bad by individuals; and things that are perceived as evil or bad
are either natural events (natural disasters or illnesses) or caused by
humanity's free will. Much more the behavior of beings with free will,
then they disobey God's orders, harming others or putting themselves
over God or others, is considered to be evil.
Evil doesn't necessarily refer to evil as an ontological or moral
category, but often to harm or as the intention and consequence of an
action, but also to unlawfull actions.
Unproductive actions or those who do not produce benefits are also thought of as evil.
A typical understanding of evil is reflected by Al-Ash`ari founder of Asharism.
Accordingly, qualifying something as evil depends on the circumstances
of the observer. An event or an action itself is neutral, but it
receives its qualification by God. Since God is omnipotent and nothing
can exist outside of God's power, God's will determine, whether or not
something is evil.
Judaism
In Judaism, evil is not real, it is per se
not part of God's creation, but comes into existence through man's bad
actions. Human beings are responsible for their choices, and so have the
free will to choose good (life in olam haba) or bad (death in heaven). (Deuteronomy 28:20) Judaism stresses obedience to God's 613 commandments of the Written Torah (see also Tanakh) and the collective body of Jewish religious laws expounded in the Oral Torah and Shulchan Aruch (see also Mishnah and the Talmud). In Judaism, there is no prejudice in one's becoming good or evil at the time of birth, since full responsibility comes with Bar and Bat Mitzvah, when Jewish boys become 13, and girls become 12 years old.
Ancient Egyptian Religion
Evil in the religion of ancient Egypt is known as Isfet, "disorder/violence". It is the opposite of Maat, "order", and embodied by the serpent god Apep, who routinely attempts to kill the sun godRa
and is stopped by nearly every other deity. Isfet is not a primordial
force, but the consequence of free will and an individual's struggle
against the non-existence embodied by Apep, as evidenced by the fact
that it was born from Ra's umbilical cord instead of being recorded in
the religion's creation myths.
The primal duality in Buddhism is between suffering and enlightenment, so the good vs. evil splitting has no direct analogue in it. One may infer from the general teachings of the Buddha that the catalogued causes of suffering are what correspond in this belief system to 'evil'.
Practically this can refer to 1) the three selfish
emotions—desire, hate and delusion; and 2) to their expression in
physical and verbal actions. See ten unvirtuous actions in Buddhism. Specifically, evil
means whatever harms or obstructs the causes for happiness in this
life, a better rebirth, liberation from samsara, and the true and
complete enlightenment of a buddha (samyaksambodhi).
"What is evil? Killing is evil, lying is evil, slandering is
evil, abuse is evil, gossip is evil: envy is evil, hatred is evil, to
cling to false doctrine is evil; all these things are evil. And what is
the root of evil? Desire is the root of evil, illusion is the root of
evil." Gautama Siddhartha, the founder of Buddhism, 563–483 BC.
Hinduism
In Hinduism, the concept of Dharma or righteousness clearly divides the world into good and evil, and clearly explains that wars have to be waged sometimes to establish and protect Dharma, this war is called Dharmayuddha. This division of good and evil is of major importance in both the Hindu epics of Ramayana and Mahabharata. The main emphasis in Hinduism is on bad action, rather than bad people. The Hindu holy text, the Bhagavad Gita, speaks of the balance of good and evil. When this balance goes off, divine incarnations come to help to restore this balance.
Sikhism
In
adherence to the core principle of spiritual evolution, the Sikh idea of
evil changes depending on one's position on the path to liberation. At
the beginning stages of spiritual growth, good and evil may seem neatly
separated. Once one's spirit evolves to the point where it sees most
clearly, the idea of evil vanishes and the truth is revealed. In his
writings Guru Arjan
explains that, because God is the source of all things, what we believe
to be evil must too come from God. And because God is ultimately a
source of absolute good, nothing truly evil can originate from God.
Nevertheless, Sikhism, like many other religions, does
incorporate a list of "vices" from which suffering, corruption, and
abject negativity arise. These are known as the Five Thieves, called such due to their propensity to cloud the mind and lead one astray from the prosecution of righteous action. These are:
One who gives in to the temptations of the Five Thieves is known as "Manmukh", or someone who lives selfishly and without virtue. Inversely, the "Gurmukh,
who thrive in their reverence toward divine knowledge, rise above vice
via the practice of the high virtues of Sikhism. These are:
In the originally Persian religion of Zoroastrianism, the world is a battleground between the god Ahura Mazda (also called Ormazd) and the malignant spirit Angra Mainyu (also called Ahriman). The final resolution of the struggle between good and evil was supposed to occur on a day of Judgement,
in which all beings that have lived will be led across a bridge of
fire, and those who are evil will be cast down forever. In Afghan
belief, angels and saints are beings sent to help us achieve the path towards goodness.
Question of a universal definition
A
fundamental question is whether there is a universal, transcendent
definition of evil, or whether evil is determined by one's social or
cultural background. C. S. Lewis, in The Abolition of Man, maintained that there are certain acts that are universally considered evil, such as rape and murder.
The numerous instances in which rape or murder is morally affected by
social context call this into question. Up until the mid-19th century,
the United States—along with many other countries—practiced forms of slavery.
As is often the case, those transgressing moral boundaries stood to
profit from that exercise. Arguably, slavery has always been the same
and objectively evil, but men with a motivation to transgress will
justify that action.
Adolf Hitler is sometimes used as a modern symbol of evil. Hitler's policies and orders resulted in the deaths of about 40 million people.
The Nazis, during World War II, considered genocide to be acceptable, as did the HutuInterahamwe in the Rwandan genocide.
One might point out, though, that the actual perpetrators of those
atrocities probably avoided calling their actions genocide, since the
objective meaning of any act accurately described by that word is to
wrongfully kill a selected group of people, which is an action that at
least their victims will understand to be evil. Universalists consider
evil independent of culture, and wholly related to acts or intents.
Thus, while the ideological leaders of Nazism and the Hutu Interhamwe
accepted (and considered it moral) to commit genocide, the belief in
genocide as fundamentally or universally evil holds that
those who instigated this genocide are actually evil. Hitler considered
it a moral duty to destroy Jews because he saw them as the root of all
of Germany's ills and the violence associated with communism. Osama bin Laden
saw Islam as under attack by Western and US influence, accusing the US
and Israel of forming a Crusader-Zionist alliance to destroy Islam, and
considering US troops in Saudi Arabia infidels in the land of Islam's
two holiest sites. He therefore considered non-Muslims and Shiite
Muslims evil people intent on destroying Islamic purity and therefore
heretic.
Given his mixed record of efforts to give the Cuban people
free-of-charge healthcare and education as well as opposing US hegemony
in Latin America, while crushing all opposition and wrecking the Cuban
economy, Fidel Castro saw himself as a Caribbean Robin Hood who considered the US and capitalism evil, while anti-Castro Cuban Americans,
Cuban dissidents, and other anti-communists saw Castro as the
personification of evil in late 20th-century Cuban and Latin American
history, viewing his Castroist ideology as just as evil as any other
form of communism and bashing him for locking up dissidents and killing
innocents by firing squads, while creating mayhem in the developing
world by working to foment violent communist revolutions in the Americas
and many African countries.
Philosophical questions
Approaches
Views on the nature of evil belong to the branch of philosophy known as ethics—which in modern philosophy is subsumed into three major areas of study:
Meta-ethics, that seeks to understand the nature of ethical properties, statements, attitudes, and judgments.
Normative ethics, investigates the set of questions that arise when considering how one ought to act, morally speaking.
Applied ethics, concerned with the analysis of particular moral issues in private and public life.
Usefulness as a term
One school of thought that holds that no person is evil and that only acts may be properly considered evil. Psychologist and mediator Marshall Rosenberg claims that the root of violence is the very concept of evil or badness.
When we label someone as bad or evil, Rosenberg claims, it invokes the
desire to punish or inflict pain. It also makes it easy for us to turn
off our feelings towards the person we are harming. He cites the use of
language in Nazi Germany as being a key to how the German people were
able to do things to other human beings that they normally would not do.
He links the concept of evil to our judicial system, which seeks to
create justice via punishment—punitive justice—punishing acts that are seen as bad or wrong.He contrasts this approach with what he found in cultures where the idea of evil was non-existent. In such cultures
when someone harms another person, they are believed to be out of
harmony with themselves and their community, are seen as sick or ill and
measures are taken to restore them to a sense of harmonious relations
with themselves and others.
Psychologist Albert Ellis agrees, in his school of psychology called Rational Emotive Behavioral Therapy,
or REBT. He says the root of anger, and the desire to harm someone, is
almost always related to variations of implicit or explicit
philosophical beliefs about other human beings. He further claims that
without holding variants of those covert or overt belief and
assumptions, the tendency to resort to violence in most cases is less
likely.
American psychiatrist M. Scott Peck on the other hand, describes evil as militant ignorance. The original Judeo-Christian concept of sin is as a process that leads one to miss the mark
and not achieve perfection. Peck argues that while most people are
conscious of this at least on some level, those that are evil actively
and militantly refuse this consciousness. Peck describes evil as a
malignant type of self-righteousness which results in a projection of
evil onto selected specific innocent victims (often children or other
people in relatively powerless positions). Peck considers those he calls
evil to be attempting to escape and hide from their own conscience
(through self-deception) and views this as being quite distinct from the
apparent absence of conscience evident in sociopaths.
According to Peck, an evil person:
Is consistently self-deceiving, with the intent of avoiding guilt and maintaining a self-image of perfection
Deceives others as a consequence of their own self-deception
Psychologically projects his or her evils and sins onto very specific targets, scapegoating those targets while treating everyone else normally ("their insensitivity toward him was selective")
Commonly hates with the pretense of love, for the purposes of self-deception as much as the deception of others
Abuses political or emotional power ("the imposition of one's will upon others by overt or covert coercion")
Maintains a high level of respectability and lies incessantly in order to do so
Is consistent with his or her sins. Evil people are defined not so
much by the magnitude of their sins, but by their consistency (of
destructiveness)
Is unable to think from the viewpoint of their victim
He also considers certain institutions may be evil, as his discussion of the My Lai Massacre and its attempted coverup illustrate. By this definition, acts of criminal and state terrorism would also be considered evil.
Necessity
Martin Luther believed that occasional minor evil could have a positive effect
Martin Luther
argued that there are cases where a little evil is a positive good. He
wrote, "Seek out the society of your boon companions, drink, play, talk
bawdy, and amuse yourself. One must sometimes commit a sin out of hate
and contempt for the Devil, so as not to give him the chance to make one scrupulous over mere nothings ... "
According to the "realist" schools of political philosophy,
leaders should be indifferent to good or evil, taking actions based only
upon advantage; this approach to politics was put forth most famously
by Niccolò Machiavelli, a 16th-century Florentine writer who advised tyrants that "it is far safer to be feared than loved."
The international relations theories of realism and neorealism, sometimes called realpolitik advise politicians to explicitly ban absolute moral and ethical
considerations from international politics, and to focus on
self-interest, political survival, and power politics, which they hold
to be more accurate in explaining a world they view as explicitly amoral
and dangerous. Political realists usually justify their perspectives by
stating that morals and politics should be separated as two unrelated
things, as exerting authority often involves doing something not moral.
Machiavelli wrote: "there will be traits considered good that, if
followed, will lead to ruin, while other traits, considered vices which
if practiced achieve security and well being for the prince."
Anton LaVey, founder of the Church of Satan,
was a materialist and claimed that evil is actually good. He was
responding to the common practice of describing sexuality or disbelief
as evil, and his claim was that when the word evil is used to
describe the natural pleasures and instincts of men and women or the
skepticism of an inquiring mind, the things called and feared as evil
are really non-evil and in fact good.
A dream is a succession of images, ideas, emotions, and sensations that usually occur involuntarily in the mind during certain stages of sleep.
The content and purpose of dreams are not fully understood, although
they have been a topic of scientific, philosophical and religious
interest throughout recorded history. Dream interpretation
is the attempt at drawing meaning from dreams and searching for an
underlying message. The scientific study of dreams is called oneirology.
Dreams mainly occur in the rapid-eye movement (REM) stage of sleep—when brain activity
is high and resembles that of being awake. REM sleep is revealed by
continuous movements of the eyes during sleep. At times, dreams may
occur during other stages of sleep. However, these dreams tend to be much less vivid or memorable. The length of a dream can vary; they may last for a few seconds, or approximately 20–30 minutes.
People are more likely to remember the dream if they are awakened
during the REM phase. The average person has three to five dreams per
night, and some may have up to seven; however, most dreams are immediately or quickly forgotten.
Dreams tend to last longer as the night progresses. During a full
eight-hour night sleep, most dreams occur in the typical two hours of
REM. Dreams related to waking-life experiences are associated with REM theta activity, which suggests that emotional memory processing takes place in REM sleep.
Opinions about the meaning of dreams have varied and shifted through time and culture. Many endorse the Freudian theory of dreams – that dreams reveal insight into hidden desires and emotions.
Other prominent theories include those suggesting that dreams assist in
memory formation, problem solving, or simply are a product of random
brain activation.
Sigmund Freud, who developed the psychological discipline of psychoanalysis, wrote extensively about dream theories and their interpretations in the early 1900s. He explained dreams as manifestations of one's deepest desires and anxieties, often relating to repressedchildhood memories
or obsessions. Furthermore, he believed that virtually every dream
topic, regardless of its content, represented the release of sexual
tension. In The Interpretation of Dreams
(1899), Freud developed a psychological technique to interpret dreams
and devised a series of guidelines to understand the symbols and motifs
that appear in our dreams. In modern times, dreams have been seen as a
connection to the unconscious mind. They range from normal and ordinary to overly surreal and bizarre. Dreams can have varying natures, such as being frightening, exciting, magical, melancholic, adventurous, or sexual. The events in dreams are generally outside the control of the dreamer, with the exception of lucid dreaming, where the dreamer is self-aware. Dreams can at times make a creative thought occur to the person or give a sense of inspiration.
Cultural meaning
Ancient history
The Dreaming is a common term within the animist creation narrative of indigenous Australians for a personal, or group, creation and for what may be understood as the "timeless time" of formative creation and perpetual creating.
The ancient Sumerians in Mesopotamia have left evidence of dream interpretation dating back to at least 3100 BC. Throughout Mesopotamian history, dreams were always held to be extremely important for divination and Mesopotamian kings paid close attention to them. Gudea, the king of the Sumerian city-state of Lagash (reigned c. 2144–2124 BC), rebuilt the temple of Ningirsu as the result of a dream in which he was told to do so. The standard AkkadianEpic of Gilgamesh contains numerous accounts of the prophetic power of dreams. First, Gilgamesh himself has two dreams foretelling the arrival of Enkidu. Later, Enkidu dreams about the heroes' encounter with the giant Humbaba. Dreams were also sometimes seen as a means of seeing into other worlds
and it was thought that the soul, or some part of it, moved out of the
body of the sleeping person and actually visited the places and persons
the dreamer saw in his or her sleep. In Tablet VII of the epic, Enkidu recounts to Gilgamesh a dream in which he saw the gods Anu, Enlil, and Shamash condemn him to death. He also has a dream in which he visits the Underworld.
The Assyrian king Ashurnasirpal II (reigned 883–859 BC) built a temple to Mamu, possibly the god of dreams, at Imgur-Enlil, near Kalhu. The later Assyrian king Ashurbanipal (reigned 668–c. 627 BC) had a dream during a desperate military situation in which his divine patron, the goddess Ishtar, appeared to him and promised that she would lead him to victory. The Babylonians and Assyrians divided dreams into "good," which were sent by the gods, and "bad," sent by demons. A surviving collection of dream omens entitled Iškar Zaqīqu records various dream scenarios as well as prognostications of what will happen to the person who experiences each dream, apparently based on previous cases. Some list different possible outcomes, based on occasions in which people experienced similar dreams with different results. Dream scenarios mentioned include a variety of daily work events, journeys to different locations, family matters, sex acts, and encounters with human individuals, animals, and deities.
In ancient Egypt, as far back as 2000 BC, the Egyptians wrote down their dreams on papyrus. People with vivid and significant dreams were thought to be blessed and were considered special. Ancient Egyptians believed that dreams were like oracles,
bringing messages from the gods. They thought that the best way to
receive divine revelation was through dreaming and thus they would
induce (or "incubate") dreams. Egyptians would go to sanctuaries and
sleep on special "dream beds" in hope of receiving advice, comfort, or
healing from the gods.
In Chinese history, people wrote of two vital aspects of the soul of which one is freed from the body during slumber to journey in a dream realm, while the other remained in the body, although this belief and dream interpretation had been questioned since early times, such as by the philosopher Wang Chong (27–97 AD). The Indian text Upanishads,
written between 900 and 500 BC, emphasizes two meanings of dreams. The
first says that dreams are merely expressions of inner desires. The
second is the belief of the soul leaving the body and being guided until
awakened.
The Greeks shared their beliefs with the Egyptians on how to interpret good and bad dreams, and the idea of incubating dreams. Morpheus,
the Greek god of dreams, also sent warnings and prophecies to those who
slept at shrines and temples. The earliest Greek beliefs about dreams
were that their gods physically visited the dreamers, where they entered
through a keyhole, exiting the same way after the divine message was
given.
Antiphon
wrote the first known Greek book on dreams in the 5th century BC. In
that century, other cultures influenced Greeks to develop the belief
that souls left the sleeping body. Hippocrates
(469–399 BC) had a simple dream theory: during the day, the soul
receives images; during the night, it produces images. Greek philosopher
Aristotle (384–322 BC) believed dreams caused physiological activity. He thought dreams could analyze illness and predict diseases. Marcus Tullius Cicero, for his part, believed that all dreams are produced by thoughts and conversations a dreamer had during the preceding days. Cicero's Somnium Scipionis described a lengthy dream vision, which in turn was commented on by Macrobius in his Commentarii in Somnium Scipionis.
Herodotus in his The Histories,
writes "The visions that occur to us in dreams are, more often than
not, the things we have been concerned about during the day."
In Welsh history, The Dream of Rhonabwy (Welsh: Breuddwyd Rhonabwy) is a Middle Welsh prose tale. Set during the reign of Madog ap Maredudd, prince of Powys (died 1160), it is dated to the late 12th or 13th century. It survives in only one manuscript, the Red Book of Hergest, and has been associated with the Mabinogion since its publication by Lady Charlotte Guest in the 19th century. The bulk of the narrative describes a dream vision experienced by its central character, Rhonabwy, a retainer of Madog, in which he visits the time of King Arthur.
Also in Welsh history, the tale 'The Dream of Macsen Wledig' is a romanticised story about the Roman emperor Magnus Maximus, called Macsen Wledig in Welsh. Born in Hispania, he became a legionary commander in Britain, assembled a Celtic army and assumed the title of Emperor of the Western Roman Empire in 383. He was defeated in battle in 385 and beheaded at the direction of the Eastern Roman emperor.
In Judaism, dreams are considered part of the experience of the world
that can be interpreted and from which lessons can be garnered. It is
discussed in the Talmud, Tractate Berachot 55–60.
The ancient Hebrews connected their dreams heavily with their religion, though the Hebrews were monotheistic
and believed that dreams were the voice of one God alone. Hebrews also
differentiated between good dreams (from God) and bad dreams (from evil
spirits). The Hebrews, like many other ancient cultures, incubated
dreams in order to receive a divine revelation. For example, the Hebrew
prophet Samuel would "lie down and sleep in the temple at Shiloh before
the Ark and receive the word of the Lord." Most of the dreams in the Bible are in the Book of Genesis.
Christians mostly shared the beliefs of the Hebrews and thought that dreams were of a supernatural character because the Old Testament includes frequent stories of dreams with divine inspiration. The most famous of these dream stories was Jacob's dream of a ladder that stretches from Earth to Heaven. Many Christians preach that God can speak to people through their dreams. The famous glossary, the Somniale Danielis, written in the name of Daniel, attempted to teach Christian populations to interpret their dreams.
Iain R. Edgar has researched the role of dreams in Islam.
He has argued that dreams play an important role in the history of
Islam and the lives of Muslims, since dream interpretation is the only
way that Muslims can receive revelations from God since the death of the
last prophet, Muhammad.
In Hinduism
In the Mandukya Upanishad, part of the Veda scriptures of Indian Hinduism,
a dream is one of three states that the soul experiences during its
lifetime, the other two states being the waking state and the sleep
state.
In Buddhism
In Buddhism, ideas about dreams are similar to the classical and folk
traditions in South Asia. The same dream is sometimes experienced by
multiple people, as in the case of the Buddha-to-be, before he is leaving his home. It is described in the Mahāvastu
that several of the Buddha's relatives had premonitory dreams preceding
this. Some dreams are also seen to transcend time: the Buddha-to-be has
certain dreams that are the same as those of previous Buddhas, the Lalitavistara
states. In Buddhist literature, dreams often function as a "signpost"
motif to mark certain stages in the life of the main character.
A Dream of a Girl Before a Sunrise by Karl Bryullov (1830–1833)
Some philosophers have concluded that what we think of as the "real world" could be or is an illusion (an idea known as the skeptical hypothesis about ontology).
The first recorded mention of the idea was by Zhuangzi, and it is also discussed in Hinduism, which makes extensive use of the argument in its writings. It was formally introduced to Western philosophy by Descartes in the 17th century in his Meditations on First Philosophy. Stimulus, usually an auditory one, becomes a part of a dream, eventually then awakening the dreamer.
Postclassical and medieval history
Some Indigenous American tribes and Mexican civilizations believe that dreams are a way of visiting and having contact with their ancestors. Some Native American tribes used vision quests
as a rite of passage, fasting and praying until an anticipated guiding
dream was received, to be shared with the rest of the tribe upon their
return.
The Middle Ages brought a harsh interpretation of dreams. They were seen as evil, and the images as temptations from the devil. Many believed that during sleep, the devil could fill the human mind with corrupting and harmful thoughts. Martin Luther, the ProtestantReformer, believed dreams were the work of the Devil. However, Catholics such as St. Augustine and St. Jerome claimed that the direction of their lives was heavily influenced by their dreams.
An artist's illustration of Saint Joseph dreaming.
Self-portrait of a Dreamer
Modern popular culture often conceives of dreams, like Freud, as expressions of the dreamer's deepest fears and desires. The film version of The Wizard of Oz
(1939) depicts a full-color dream that causes Dorothy to perceive her
black-and-white reality and those with whom she shares it in a new way.
In films such as Spellbound (1945), The Manchurian Candidate (1962), and Inception (2010), the protagonists must extract vital clues from surreal dreams.
Most dreams in popular culture are, however, not symbolic, but
straightforward and realistic depictions of their dreamer's fears and
desires.
Dream scenes may be indistinguishable from those set in the dreamer's
real world, a narrative device that undermines the dreamer's and the
audience's sense of security and allows horror film protagonists, such as those of Carrie (1976), Friday the 13th (1980) or An American Werewolf in London (1981) to be suddenly attacked by dark forces while resting in seemingly safe places.
In speculative fiction, the line between dreams and reality may be blurred even more in the service of the story. Dreams may be psychically invaded or manipulated (Dreamscape, 1984; the Nightmare on Elm Street films, 1984–2010; Inception, 2010) or even come literally true (as in The Lathe of Heaven, 1971). In Ursula K. Le Guin's book, The Lathe of Heaven (1971), the protagonist finds that his "effective" dreams can retroactively change reality. Peter Weir's 1977 Australian film The Last Wave
makes a simple and straightforward postulate about the premonitory
nature of dreams (from one of his Aboriginal characters) that
"... dreams are the shadow of something real". In Kyell Gold's novel Green Fairy from the Dangerous Spirits
series, the protagonist, Sol, experiences the memories of a dancer who
died 100 years before through Absinthe induced dreams and after each
dream something from it materializes into his reality. Such stories play
to audiences' experiences with their own dreams, which feel as real to
them.
Neurobiology
REM versus non-REM sleep dreaming
Distinct types of dreams have been identified for REM and non-REM
sleep stages. The vivid bizarre dreams that are commonly remembered
upon waking up are primarily associated with REM sleep. Deep (stage 3
and 4) slow-wave sleep (NREM sleep) is commonly associated with more static, thoughtful dreams. These dreams are primarily driven by the hippocampus in the process of long-term memory consolidation
and predominantly include memories of events “as they happened” without
the random novel combination of objects seen in REM sleep dreams. The
rest of the article focuses on REM sleep dreaming, thereafter simply
referred as dreaming.
Since waking up usually happens during rapid eye movement sleep (REM), the vivid bizarre REM sleep dreams are the most common type of dreams that is remembered. (During REM sleep an electroencephalogram
(EEG) shows brain activity that, among sleep states, is most like
wakefulness.) During a typical lifespan, a person spends a total of
about six years dreaming (which is about two hours each night). Most dreams only last 5 to 20 minutes.
It is unknown where in the brain dreams originate, if there is a single
origin for dreams or if multiple portions of the brain are involved, or
what the purpose of dreaming is for the body or mind.
During most dreams, the person dreaming is not aware that they
are dreaming, no matter how absurd or eccentric the dream is. The reason
for this may be that the prefrontal cortex,
the region of the brain responsible for logic and planning, exhibits
decreased activity during dreams. This allows the dreamer to more
actively interact with the dream without thinking about what might
happen, since things that would normally stand out in reality blend in
with the dream scenery.
When REM sleep episodes were timed for their duration and
subjects were awakened to make reports before major editing or
forgetting of their dreams could take place, subjects accurately
reported the length of time they had been dreaming in an REM sleep
state. Some researchers have speculated that "time dilation" effects only seem to be taking place upon reflection and do not truly occur within dreams.
This close correlation of REM sleep and dream experience was the basis
of the first series of reports describing the nature of dreaming: that
it is a regular nightly rather than occasional phenomenon, and is
correlated with high-frequency activity within each sleep period
occurring at predictable intervals of approximately every 60–90 minutes
in all humans throughout the lifespan.
REM sleep episodes and the dreams that accompany them lengthen
progressively through the night, with the first episode being the
shortest, of approximately 10–12 minutes duration, and the second and
third episodes increasing to 15–20 minutes. Dreams at the end of the
night may last as long as 15 minutes, although these may be experienced
as several distinct episodes due to momentary arousals interrupting
sleep as the night ends. Dream reports can be reported from normal
subjects 50% of the time when they are awakened prior to the end of the
first REM period. This rate of retrieval is increased to about 99% when
awakenings are made from the last REM period of the night. The increase
in the ability to recall dreams appears related to intensification
across the night in the vividness of dream imagery, colors, and
emotions.
Brain activity
One of the central questions of sleep research is what part of the
brain is driving dreams' video-auditory experience. During waking, most
of the mind's internal imagery is controlled from the front of the brain
by the lateral prefrontal cortex (LPFC). Reasoning, planning, and strategizing are the results of the constructive imagination
conducted by the LPFC, which acts like a puppeteer assembling objects
stored in memory into novel combinations. During REM sleep, however the
LPFC is inactive. Furthermore, in people whose LPFC is damaged, dreams do not change at all, confirming that LPFC does not control dreaming.
During deep slow-wave sleep, imagery is primarily driven by the hippocampus in the process of long-term memory consolidation
and predominantly includes memories of events “as they happened”
without the random novel combination of objects seen in REM sleep
dreams. During REM sleep, however, the communication between the neocortex and the hippocampus is disrupted by a high ACh level.
Without being driven by the LPFC (as in waking) and hippocampus (as in slow-wave sleep), it is unclear how exactly images appear in one's perception during REM sleep. A common explanation is that neuronal ensembles in the posterior cortical hot zone, primed by previous activity or current sensory or subcortical stimulation, activate spontaneously, triggered by the ponto-geniculo-occipital (PGO) waves that characterize REM sleep.
In the words of Hobson & McCarley, the neocortex is making “the
best of a bad job in producing even partially coherent dream imagery
from the relatively noisy signals sent up from the brain stem.”
It is also commonly accepted that the intensity of dreams during
REM sleep can be dialed up or down by the dopaminergic cells of the ventral tegmental area. For example, drugs that block dopaminergic activity (e.g., haloperidol) inhibit unusually frequent and vivid dreaming, while the increase of dopamine (e.g., through l-dopa) stimulates excessive vivid dreaming and nightmares.
In other animal species
REM sleep and the ability to dream seem to be embedded in the biology
of many animals in addition to humans. Scientific research suggests
that all mammals experience REM.
The range of REM can be seen across species: dolphins experience
minimal REM, while humans are in the middle of the scale and the armadillo and the opossum (a marsupial) are among the most prolific dreamers, judging from their REM patterns.
Studies have observed signs of dreaming in all mammals studied,
including monkeys, dogs, cats, rats, elephants, and shrews. There have
also been signs of dreaming in birds and reptiles.
Sleeping and dreaming are intertwined. Scientific research results
regarding the function of dreaming in animals remain disputable;
however, the function of sleeping in living organisms is increasingly
clear. For example, sleep deprivation experiments conducted on rats and
other animals have resulted in the deterioration of physiological
functioning and actual tissue damage.
Some scientists argue that humans dream for the same reason other amniotes
do. From a Darwinian perspective dreams would have to fulfill some kind
of biological requirement, provide some benefit for natural selection
to take place, or at least have no negative impact on fitness. In 2000
Antti Revonsuo, a professor at the University of Turku in Finland,
claimed that centuries ago dreams would prepare humans for recognizing
and avoiding danger by presenting a simulation of threatening events.
The theory has therefore been called the threat-simulation theory.
According to Tsoukalas (2012) dreaming is related to the reactive
patterns elicited by encounters with predators, a fact that is still
evident in the control mechanisms of REM sleep (see below).
Function
Many hypotheses have been proposed as to what function dreams
perform, some of which have been contradicted by later empirical
studies. It has also been proposed that dreams serve no particular
purpose, and that they are simply a byproduct of biochemical processes
that only occur in the brain during sleep.
Dynamic psychiatry
Freud's view
In the late 19th century, psychotherapist Sigmund Freud developed a theory (since discredited) that the content of dreams is driven by unconscious wish fulfillment. Freud called dreams the "royal road to the unconscious."
He theorized that the content of dreams reflects the dreamer's
unconscious mind and specifically that dream content is shaped by
unconscious wish fulfillment. He argued that important unconscious
desires often relate to early childhood memories and experiences.
Freud's theory describes dreams as having both manifest and latent content. Latent content relates to deep unconscious wishes or fantasies while manifest content is superficial and meaningless. Manifest content often masks or obscures latent content.
In his early work, Freud argued that the vast majority of latent
dream content is sexual in nature, but he later moved away from this
categorical position. In Beyond the Pleasure Principle he considered how trauma or aggression could influence dream content. He also discussed supernatural origins in Dreams and Occultism, a lecture published in New Introductory Lectures on Psychoanalysis.
Late in life Freud acknowledged that "It is impossible to
classify as wish fulfillments" the repetitive nightmares associated with
posttraumatic stress disorder. Modern experimental studies weigh
against many of Freud's theories regarding dreams. Freud's "dream-work"
interpretation strategies have not been found to have empirical
validity. His theory that dreams were the "guardians" of sleep,
repressing and disguising bodily urges to ensure sleep continues, seems
unlikely given studies of individuals who can sleep without dreaming.
His assertions that repressed memory in infants re-surface decades later
in adult dreams conflicts with modern research on memory. Freud's
theory has difficulty explaining why young children have static and
bland dreams, or why the emotions in most dreams are negative. On the
plus side, modern researchers agree with Freud that dreams do have
coherence, and that dream content connects to other psychological
variables and often connect to recent waking thoughts (though not as
often as Freud supposed). Despite the lack of scientific evidence, dream interpretation services based on Freudian or other systems remain popular.
Jung's view
Carl Jung
rejected many of Freud's theories. Jung expanded on Freud's idea that
dream content relates to the dreamer's unconscious desires. He described
dreams as messages
to the dreamer and argued that dreamers should pay attention for their
own good. He came to believe that dreams present the dreamer with
revelations that can uncover and help to resolve emotional or religious problems and fears.
Jung wrote that recurring dreams
show up repeatedly to demand attention, suggesting that the dreamer is
neglecting an issue related to the dream. He called this "compensation."
The dream balances the conscious belief and attitudes with an
alternative. Jung did not believe that the conscious attitude was wrong
and that the dream provided the true belief. He argued that good work
with dreams takes both into account and comes up with a balanced
viewpoint. He believed that many of the symbols or images from these
dreams return with each dream. Jung believed that memories formed
throughout the day also play a role in dreaming. These memories leave
impressions for the unconscious to deal with when the ego is at rest.
The unconscious mind re-enacts these glimpses of the past in the form of
a dream. Jung called this a day residue.
Jung also argued that dreaming is not a purely individual concern, that
all dreams are part of "one great web of psychological factors."
Fritz Perls' view
Fritz Perls presented his theory of dreams as part of the holistic nature of Gestalt therapy. Dreams are seen as projections of parts of the self that have been ignored, rejected, or suppressed.
Jung argued that one could consider every person in the dream to
represent an aspect of the dreamer, which he called the subjective
approach to dreams. Perls
expanded this point of view to say that even inanimate objects in the
dream may represent aspects of the dreamer. The dreamer may, therefore,
be asked to imagine being an object in the dream and to describe it, in
order to bring into awareness the characteristics of the object that
correspond with the dreamer's personality.
Neurological theories
Activation synthesis theory
In 1976 J. Allan Hobson and Robert McCarley proposed a new theory that changed dream research, challenging the previously held Freudian
view of dreams as unconscious wishes to be interpreted. They assume
that the same structures that induce REM sleep also generate sensory
information. Hobson's 1976 research suggested that the signals
interpreted as dreams originate in the brainstem during REM sleep.
According to Hobson and other researchers, circuits in the brainstem are
activated during REM sleep. Once these circuits are activated, areas of
the limbic system involved in emotions, sensations, and memories,
including the amygdala and hippocampus, become active. The brain
synthesizes and interprets these activities; for example, changes in the
physical environment such as temperature and humidity, or physical
stimuli such as ejaculation, and attempts to create meaning from these
signals, result in dreaming.
However, research by Mark Solms suggests that dreams are generated in the forebrain, and that REM sleep and dreaming are not directly related. While working in the neurosurgery department at hospitals in Johannesburg and London,
Solms had access to patients with various brain injuries. He began to
question patients about their dreams and confirmed that patients with
damage to the parietal lobe
stopped dreaming; this finding was in line with Hobson's 1977 theory.
However, Solms did not encounter cases of loss of dreaming with patients
having brainstem damage. This observation forced him to question
Hobson's prevailing theory, which marked the brainstem as the source of
the signals interpreted as dreams.
Continual-activation theory
Combining Hobson's activation synthesis hypothesis with Solms'
findings, the continual-activation theory of dreaming presented by Jie
Zhang proposes that dreaming is a result of brain activation and
synthesis; at the same time, dreaming and REM sleep are controlled by
different brain mechanisms. Zhang hypothesizes that the function of
sleep is to process, encode, and transfer the data from the temporary
memory store to the long-term memory store. During NREM
sleep the conscious-related memory (declarative memory) is processed,
and during REM sleep the unconscious-related memory (procedural memory)
is processed.
Zhang assumes that during REM sleep the unconscious part of a
brain is busy processing the procedural memory; meanwhile, the level of
activation in the conscious part of the brain descends to a very low
level as the inputs from the sensory systems are basically disconnected.
This triggers the "continual-activation" mechanism to generate a data
stream from the memory stores to flow through the conscious part of the
brain. Zhang suggests that this pulsatile brain activation is the
inducer of each dream. He proposes that, with the involvement of the
brain associative thinking system, dreaming is, thereafter,
self-maintained with the dreamer's own thinking until the next pulse of
memory insertion. This explains why dreams have both characteristics of
continuity (within a dream) and sudden changes (between two dreams). A detailed explanation of how a dream is synthesized is given in a later paper.
Defensive immobilization: the precursor
According to Tsoukalas (2012) REM sleep is an evolutionary transformation of a well-known defensive mechanism, the tonic immobility
reflex. This reflex, also known as animal hypnosis or death feigning,
functions as the last line of defense against an attacking predator and
consists of the total immobilization of the animal: the animal appears
dead (cf. "playing possum"). Tsoukalas claims that the neurophysiology
and phenomenology of this reaction shows striking similarities to REM
sleep, a fact that suggests a deep evolutionary kinship. For example,
both reactions exhibit brainstem control, paralysis, hippocampal theta
and thermoregulatory changes. Tsoukalas claims that this theory
integrates many earlier findings into a unified framework.
As excitations of long-term memory
Eugen Tarnow suggests that dreams are ever-present excitations of long-term memory, even during waking life. The strangeness of dreams is due to the format of long-term memory, reminiscent of Penfield & Rasmussen's findings that electrical excitations of the cortex
give rise to experiences similar to dreams. During waking life an
executive function interprets long-term memory consistent with reality
checking. Tarnow's theory is a reworking of Freud's theory of dreams in
which Freud's unconscious is replaced with the long-term memory system
and Freud's "Dream Work" describes the structure of long-term memory.
A 2001 study showed evidence that illogical locations, characters,
and dream flow may help the brain strengthen the linking and
consolidation of semantic memories. These conditions may occur because, during REM sleep, the flow of information between the hippocampus and neocortex is reduced.
Increasing levels of the stress hormone cortisol late in sleep (often during REM sleep) causes this decreased communication. One stage of memory consolidation
is the linking of distant but related memories. Payne and Nadal
hypothesize these memories are then consolidated into a smooth
narrative, similar to a process that happens when memories are created
under stress.
Robert (1886),
a physician from Hamburg, was the first who suggested that dreams are a
need and that they have the function to erase (a) sensory impressions
that were not fully worked up, and (b) ideas that were not fully
developed during the day. By the dream work, incomplete material is
either removed (suppressed) or deepened and included into memory.
Robert's ideas were cited repeatedly by Freud in his Die Traumdeutung. Hughlings Jackson (1911) viewed that sleep serves to sweep away unnecessary memories and connections from the day.
This was revised in 1983 by Crick and Mitchison's "reverse learning"
theory, which states that dreams are like the cleaning-up operations of
computers when they are offline, removing (suppressing) parasitic nodes
and other "junk" from the mind during sleep.
However, the opposite view that dreaming has an information handling,
memory-consolidating function (Hennevin and Leconte, 1971) is also
common.
Psychological theories
Role in testing and selecting mental schemas
Coutts describes
dreams as playing a central role in a two-phase sleep process that
improves the mind's ability to meet human needs during wakefulness.
During the accommodation phase, mental schemas self-modify by
incorporating dream themes. During the emotional selection
phase, dreams test prior schema accommodations. Those that appear
adaptive are retained, while those that appear maladaptive are culled.
The cycle maps to the sleep cycle, repeating several times during a
typical night's sleep. Alfred Adler
suggested that dreams are often emotional preparations for solving
problems, intoxicating an individual away from common sense toward
private logic. The residual dream feelings may either reinforce or
inhibit contemplated action.
Evolutionary psychology theories
Numerous theories state that dreaming is a random by-product of REM
sleep physiology and that it does not serve any natural purpose. Flanagan claims that "dreams are evolutionary epiphenomena" and they have no adaptive function. "Dreaming came along as a free ride on a system designed to think and to sleep."
J.A. Hobson, for different reasons, also considers dreams
epiphenomena. He believes that the substance of dreams have no
significant influence on waking actions, and most people go about their
daily lives perfectly well without remembering their dreams.
Hobson proposed the activation-synthesis theory, which states that
"there is a randomness of dream imagery and the randomness synthesizes
dream-generated images to fit the patterns of internally generated
stimulations".
This theory is based on the physiology of REM sleep, and Hobson
believes dreams are the outcome of the forebrain reacting to random
activity beginning at the brainstem. The activation-synthesis theory
hypothesizes that the peculiar nature of dreams is attributed to certain
parts of the brain trying to piece together a story out of what is
essentially bizarre information. In 2005, Hobson published a book, Thirteen Dreams that Freud Never Had, in which he analyzed his own dreams after having a stroke in 2001.
Some evolutionary psychologists believe dreams serve some adaptive function for survival. Deirdre Barrett
describes dreaming as simply "thinking in different biochemical state"
and believes people continue to work on all the same problems—personal
and objective—in that state. Her research finds that anything—math, musical composition, business dilemmas—may get solved during dreaming.
Finnish psychologist Antti Revonsuo posits that dreams have
evolved for "threat simulation" exclusively. According to the Threat
Simulation Theory he proposes, during much of human evolution physical
and interpersonal threats were serious, giving reproductive advantage to
those who survived them. Therefore, dreaming evolved to replicate these
threats and continually practice dealing with them. In support of this
theory, Revonsuo shows that contemporary dreams comprise much more
threatening events than people meet in daily non-dream life, and the
dreamer usually engages appropriately with them.
It is suggested by this theory that dreams serve the purpose of
allowing for the rehearsal of threatening scenarios in order to better
prepare an individual for real-life threats.
According to Tsoukalas (2012) the biology of dreaming is related
to the reactive patterns elicited by predatorial encounters (especially
the tonic immobility reflex), a fact that lends support to evolutionary
theories claiming that dreams specialize in threat avoidance or
emotional processing.
Other hypotheses
There are many other hypotheses about the function of dreams, including:
Dreams allow the repressed parts of the mind to be satisfied through fantasy while keeping the conscious mind from thoughts that would suddenly cause one to awaken from shock.
Ferenczi proposed that the dream, when told, may communicate something that is not being said outright.
Dreams regulate mood.
Hartmann
says dreams may function like psychotherapy, by "making connections in a
safe place" and allowing the dreamer to integrate thoughts that may be
dissociated during waking life.
LaBerge and DeGracia
have suggested that dreams may function, in part, to recombine
unconscious elements within consciousness on a temporary basis by a
process they term "mental recombination", in analogy with genetic
recombination of DNA. From a bio-computational viewpoint, mental
recombination may contribute to maintaining an optimal information
processing flexibility in brain information networks.
Content
An artist's rendering of a dream.
From the 1940s to 1985, Calvin S. Hall collected more than 50,000 dream reports at Western Reserve University. In 1966 Hall and Van De Castle published The Content Analysis of Dreams, in which they outlined a coding system to study 1,000 dream reports from college students.
Results indicated that participants from varying parts of the world
demonstrated similarity in their dream content. Hall's complete dream
reports were made publicly available in the mid-1990s by Hall's protégé William Domhoff.
Visuals
The visual nature of dreams is generally highly phantasmagoric; that
is, different locations and objects continuously blend into each other.
The visuals (including locations, characters/people, objects/artifacts)
are generally reflective of a person's memories and experiences, but
conversation can take on highly exaggerated and bizarre forms. Some
dreams may even tell elaborate stories wherein the dreamer enters
entirely new, complex worlds and awakes with ideas, thoughts and
feelings never experienced prior to the dream.
People who are blind from birth do not have visual dreams. Their dream contents are related to other senses like hearing, touch, smell and taste, whichever are present since birth.
Emotions
In the Hall study, the most common emotion experienced in dreams was anxiety. Other emotions included abandonment, anger, fear, joy, and happiness. Negative emotions were much more common than positive ones.
Sexual themes
The Hall data analysis shows that sexual dreams occur no more than 10% of the time and are more prevalent in young to mid-teens. Another study showed that 8% of both men and women's dreams have sexual content. In some cases, sexual dreams may result in orgasms or nocturnal emissions. These are colloquially known as wet dreams.
Color vs. black-and-white
A small minority of people say that they dream only in black and white. A 2008 study by a researcher at the University of Dundee
found that people who were only exposed to black-and-white television
and film in childhood reported dreaming in black and white about 25% of
the time.
Relationship with medical conditions
There is evidence that certain medical conditions (normally only
neurological conditions) can impact dreams. For instance, some people
with synesthesia
have never reported entirely black-and-white dreaming, and often have a
difficult time imagining the idea of dreaming in only black and white.
Interpretations
An artist's painting of a dream.
Common interpretations
Dream interpretation can be a result of subjective ideas and experiences. One study found that most people believe that "their dreams reveal meaningful hidden truths". In one study
conducted in the United States, South Korea and India, they found that
74% of Indians, 65% of South Koreans and 56% of Americans believed their
dream content provided them with meaningful insight into their
unconscious beliefs and desires. This Freudian view of dreaming was
believed by the largely non-scientific public significantly more than
theories of dreaming that attribute dream content to memory
consolidation, problem-solving, or random brain activity.
Importance
In the paper, Morewedge and Norton (2009) also found that people
attribute more importance to dream content than to similar thought
content that occurs while they are awake. In one study, Americans were
more likely to report that they would miss their flight if they dreamt
of their plane crashing than if they thought of their plane crashing the
night before flying (while awake), and that they would be as likely to
miss their flight if they dreamt of their plane crashing the night
before their flight as if there was an actual plane crash on the route
they intended to take.
Not all dream content was considered equally important. Participants in
their studies were more likely to perceive dreams to be meaningful when
the content of dreams was in accordance with their beliefs and desires
while awake. People were more likely to view a positive dream about a
friend to be meaningful than a positive dream about someone they
disliked, for example, and were more likely to view a negative dream
about a person they disliked as meaningful than a negative dream about a
person they liked.
Other
Therapy for recurring nightmares (often associated with posttraumatic stress disorder) can include imagining alternative scenarios that could begin at each step of the dream.
Other associated phenomena
A depiction of soldiers' dreams.
Incorporation of reality
During the night, many external stimuli may bombard the senses, but
the brain often interprets the stimulus and makes it a part of a dream
to ensure continued sleep.
Dream incorporation is a phenomenon whereby an actual sensation, such
as environmental sounds, is incorporated into dreams, such as hearing a
phone ringing in a dream while it is ringing in reality or dreaming of urination while wetting
the bed. The mind can, however, awaken an individual if they are in
danger or if trained to respond to certain sounds, such as a baby
crying.
The term "dream incorporation" is also used in research examining
the degree to which preceding daytime events become elements of dreams.
Recent studies suggest that events in the day immediately preceding,
and those about a week before, have the most influence.
Gary Alan Fine and Laura Fischer Leighton argue that “dreams are
external to the individual mind” because “1) dreams are not willed by
the individual self; 2) dreams reflect social reality; 3) dreams are
public rhetoric; and 4) dreams are collectively interpretable.”
Apparent precognition of real events
According to surveys, it is common for people to feel their dreams are predicting subsequent life events. Psychologists have explained these experiences in terms of memory biases,
namely a selective memory for accurate predictions and distorted memory
so that dreams are retrospectively fitted onto life experiences. The multi-faceted nature of dreams makes it easy to find connections between dream content and real events.
The term "veridical dream" has been used to indicate dreams that reveal
or contain truths not yet known to the dreamer, whether future events
or secrets.
In one experiment, subjects were asked to write down their dreams
in a diary. This prevented the selective memory effect, and the dreams
no longer seemed accurate about the future.
Another experiment gave subjects a fake diary of a student with
apparently precognitive dreams. This diary described events from the
person's life, as well as some predictive dreams and some non-predictive
dreams. When subjects were asked to recall the dreams they had read,
they remembered more of the successful predictions than unsuccessful
ones.
Lucid dreaming
Lucid dreaming is the conscious perception of one's state while
dreaming. In this state the dreamer may often have some degree of
control over their own actions within the dream or even the characters
and the environment of the dream. Dream control has been reported to
improve with practiced deliberate lucid dreaming, but the ability to
control aspects of the dream is not necessary for a dream to qualify as
"lucid" — a lucid dream is any dream during which the dreamer knows they
are dreaming. The occurrence of lucid dreaming has been scientifically verified.
Oneironaut is a term sometimes used for those who lucidly dream.
Communication through lucid dreaming
In 1975, psychologist Keith Hearne successfully recorded a
communication from a dreamer experiencing a lucid dream. On April 12,
1975, after agreeing to move his eyes left and right upon becoming
lucid, the subject and Hearne's co-author on the resulting article, Alan
Worsley, successfully carried out this task.
Years later, psychophysiologist Stephen LaBerge conducted similar work including:
Using eye signals to map the subjective sense of time in dreams.
Comparing the electrical activity of the brain while singing awake and while dreaming.
Studies comparing in-dream sex, arousal, and orgasm.
Communication between two dreamers has also been documented. The processes involved included EEG
monitoring, ocular signaling, incorporation of reality in the form of
red light stimuli and a coordinating website. The website tracked when
both dreamers were dreaming and sent the stimulus to one of the dreamers
where it was incorporated into the dream. This dreamer, upon becoming
lucid, signaled with eye movements; this was detected by the website
whereupon the stimulus was sent to the second dreamer, invoking
incorporation into this dream.
Absent-minded transgression
Dreams of absent-minded transgression (DAMT) are dreams wherein the
dreamer absentmindedly performs an action that he or she has been trying
to stop (one classic example is of a quitting smoker having dreams of
lighting a cigarette). Subjects who have had DAMT have reported waking
with intense feelings of guilt. One study found a positive association between having these dreams and successfully stopping the behavior.
Recall
The recollection of dreams is extremely unreliable, though it is a
skill that can be trained. Dreams can usually be recalled if a person is
awakened while dreaming. Women tend to have more frequent dream recall than men. Dreams that are difficult to recall may be characterized by relatively little affect, and factors such as salience, arousal,
and interference play a role in dream recall. Often, a dream may be
recalled upon viewing or hearing a random trigger or stimulus. The salience hypothesis
proposes that dream content that is salient, that is, novel, intense,
or unusual, is more easily remembered. There is considerable evidence
that vivid, intense, or unusual dream content is more frequently
recalled. A dream journal can be used to assist dream recall, for personal interest or psychotherapy purposes.
For some people, sensations from the previous night's dreams are
sometimes spontaneously experienced in falling asleep. However they are
usually too slight and fleeting to allow dream recall. At least 95% of
all dreams are not remembered. Certain brain chemicals necessary for
converting short-term memories into long-term ones are suppressed during
REM sleep. Unless a dream is particularly vivid and if one wakes during
or immediately after it, the content of the dream is not remembered. Recording or reconstructing dreams may one day assist with dream recall. Using technologies such as functional magnetic resonance imaging (fMRI) and electromyography (EMG), researchers have been able to record basic dream imagery, dream speech activity and dream motor behavior (such as walking and hand movements).
Individual differences
In line with the salience hypothesis, there is considerable evidence
that people who have more vivid, intense or unusual dreams show better
recall. There is evidence that continuity of consciousness is related to
recall. Specifically, people who have vivid and unusual experiences
during the day tend to have more memorable dream content and hence
better dream recall. People who score high on measures of personality
traits associated with creativity, imagination, and fantasy, such as openness to experience, daydreaming, fantasy proneness, absorption, and hypnotic susceptibility, tend to show more frequent dream recall.
There is also evidence for continuity between the bizarre aspects of
dreaming and waking experience. That is, people who report more bizarre
experiences during the day, such as people high in schizotypy (psychosis proneness) have more frequent dream recall and also report more frequent nightmares.
Déjà vu
One theory of déjà vu attributes the feeling of having previously
seen or experienced something to having dreamed about a similar
situation or place, and forgetting about it until one seems to be
mysteriously reminded of the situation or the place while awake.
Daydreaming
A daydream is a visionary fantasy, especially one of happy, pleasant thoughts, hopes or ambitions, imagined as coming to pass, and experienced while awake. There are many different types of daydreams, and there is no consistent definition amongst psychologists. The general public also uses the term for a broad variety of experiences. Research by Harvard psychologist Deirdre Barrett has found that people who experience vivid dreamlike mental images
reserve the word for these, whereas many other people refer to milder
imagery, realistic future planning, review of past memories or just
"spacing out"—i.e. one's mind going relatively blank—when they talk
about "daydreaming."'
While daydreaming has long been derided as a lazy, non-productive
pastime, it is now commonly acknowledged that daydreaming can be
constructive in some contexts. There are numerous examples of people in creative or artistic careers, such as composers, novelists and filmmakers, developing new ideas through daydreaming. Similarly, research scientists, mathematicians and physicists have developed new ideas by daydreaming about their subject areas.
Hallucination
A hallucination, in the broadest sense of the word, is a perception in the absence of a stimulus.
In a stricter sense, hallucinations are perceptions in a conscious and
awake state, in the absence of external stimuli, and have qualities of
real perception, in that they are vivid, substantial, and located in
external objective space. The latter definition distinguishes
hallucinations from the related phenomena of dreaming, which does not
involve wakefulness.
Nightmare
An artist's depiction of a woman having a nightmare.
A nightmare is an unpleasant dream that can cause a strong negative emotional response from the mind, typically fear or horror, but also despair, anxiety and great sadness.
The dream may contain situations of danger, discomfort, psychological
or physical terror. Sufferers usually awaken in a state of distress and
may be unable to return to sleep for a prolonged period of time.
Night terror
A night terror, also known as a sleep terror or pavor nocturnus, is a parasomniadisorder that predominantly affects children, causing feelings of terror or dread. Night terrors should not be confused with nightmares, which are bad dreams that cause the feeling of horror or fear.