Interpretation of dreams, engraving from an English chapbook.
Thomas Paine asleep, having a nightmare
Dream interpretation is the process of assigning meaning to dreams. In many ancient societies, such as those of Egypt and Greece,
 dreaming was considered a supernatural communication or a means of 
divine intervention, whose message could be interpreted by people with 
these associated spiritual powers. 
In modern times, various schools of psychology and neurobiology
 have offered theories about the meaning and purpose of dreams. Most 
people currently appear to interpret dream content according to the Freudian theory of dreams in countries, as found by a study conducted in the United States, India, and South Korea.
People appear to believe dreams are particularly meaningful: they
 assign more meaning to dreams than to similar waking thoughts. For 
example, people report they would be more likely to cancel a trip they 
had planned that involved a plane flight if they dreamt of their plane 
crashing the night before than if the Department of Homeland Security 
issued a Federal warning.
However, people do not attribute equal importance to all dreams. People appear to use motivated reasoning
 when interpreting their dreams. They are more likely to view dreams 
confirming their waking beliefs and desires to be more meaningful than 
dreams that contradict their waking beliefs and desires.
Early history
Early civilizations
The ancient Akkadian Epic of Gilgamesh (Tablet V pictured) contains numerous examples of dream interpretation.
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 Akkadian Epic of Gilgamesh contains numerous accounts of the prophetic power of dreams. First, Gilgamesh himself has two dreams foretelling the arrival of Enkidu.
 In one of these dreams, Gilgamesh sees an axe fall from the sky. The 
people gather around it in admiration and worship. Gilgamesh throws the 
axe in front of his mother Ninsun
 and then embraces it like a wife. Ninsun interprets the dream to mean 
that someone powerful will soon appear. Gilgamesh will struggle with him
 and try to overpower him, but he will not succeed. Eventually, they 
will become close friends and accomplish great things. She concludes, 
"That you embraced him like a wife means he will never forsake you. Thus
 your dream is solved." Later in the epic, 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 was 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.
Joseph Interprets Pharaoh's Dream (watercolor circa 1896–1902 by James Tissot)
In ancient Egypt, priests acted as dream interpreters. Hieroglyphics
 depicting dreams and their interpretations are evident. Dreams have 
been held in considerable importance through history by most cultures.
Classical Antiquity
The ancient Greeks constructed temples they called Asclepieions, where sick people were sent to be cured. It was believed that cures would be effected through divine grace by incubating dreams within the confines of the temple. Dreams were also considered prophetic or omens of particular significance. Artemidorus of Daldis, who lived in the 2nd century AD, wrote a comprehensive text Oneirocritica (The Interpretation of Dreams).
 Although Artemidorus believed that dreams can predict the future, he 
presaged many contemporary approaches to dreams. He thought that the 
meaning of a dream image could involve puns and could be understood by 
decoding the image into its component words. For example, Alexander, 
while waging war against the Tyrians, dreamt that a satyr was dancing on
 his shield. Artemidorus reports that this dream was interpreted as 
follows: satyr = sa tyros ("Tyre will be thine"), predicting that
 Alexander would be triumphant. Freud acknowledged this example of 
Artemidorus when he proposed that dreams be interpreted like a rebus.
Middle Ages
In medieval Islamic psychology, certain hadiths indicate that dreams consist of three parts, and early Muslim scholars recognized three kinds of dreams: false, patho-genetic, and true. Ibn Sirin (654–728) was renowned for his Ta'bir al-Ru'ya and Muntakhab al-Kalam fi Tabir al-Ahlam,
 a book on dreams. The work is divided into 25 sections on dream 
interpretation, from the etiquette of interpreting dreams to the 
interpretation of reciting certain Surahs of the Qur'an in one's dream. He writes that it is important for a layperson to seek assistance from an alim
 (Muslim scholar) who could guide in the interpretation of dreams with a
 proper understanding of the cultural context and other such causes and 
interpretations. Al-Kindi (Alkindus) (801–873) also wrote a treatise on dream interpretation: On Sleep and Dreams. In consciousness studies, Al-Farabi (872–951) wrote the On the Cause of Dreams, which appeared as chapter 24 of his Book of Opinions of the people of the Ideal City. It was a treatise on dreams, in which he was the first to distinguish between dream interpretation and the nature and causes of dreams. In The Canon of Medicine, Avicenna extended the theory of temperaments to encompass "emotional aspects, mental capacity, moral attitudes, self-awareness, movements and dreams." Ibn Khaldun's Muqaddimah (1377) states that "confused dreams" are "pictures of the imagination that are stored inside by perception and to which the ability to think is applied, after (man) has retired from sense perception."
Ibn Shaheen states: "Interpretations change their foundations 
according to the different conditions of the seer (of the vision), so 
seeing handcuffs during sleep is disliked but if a righteous person sees
 them it can mean stopping the hands from evil". Ibn Sirin said about a 
man who saw himself giving a sermon from the mimbar: "He will achieve 
authority and if he is not from the people who have any kind of 
authority it means that he will be crucified".
China
A standard traditional Chinese book on dream-interpretation is the Lofty Principles of Dream Interpretation (夢占逸旨) compiled in the 16th century by Chen Shiyuan (particularly the "Inner Chapters" of that opus).
 Chinese thinkers also raised profound ideas about dream interpretation,
 such as the question of how we know we are dreaming and how we know we 
are awake. It is written in the Chuang-tzu: "Once Chuang Chou dreamed 
that he was a butterfly. He fluttered about happily, quite pleased with 
the state that he was in, and knew nothing about Chuang Chou. Presently 
he awoke and found that he was very much Chuang Chou again. Now, did 
Chou dream that he was a butterfly or was the butterfly now dreaming 
that he was Chou?" This raises the question of reality monitoring in 
dreams, a topic of intense interest in modern cognitive neuroscience.
Modern Europe
In the 17th century the English physician and writer Sir Thomas Browne wrote a short tract upon the interpretation of dreams. Dream interpretation was taken up as part of psychoanalysis at the end of the 19th century; the perceived, manifest content of a dream is analyzed to reveal its latent meaning to the psyche of the dreamer. One of the seminal works on the subject is The Interpretation of Dreams by Sigmund Freud.
The Present
A paper in 2009 by Carey Morewedge and Michael Norton in the Journal of Personality and Social Psychology
 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 endorsed significantly more than theories of dreaming 
that attribute dream content to memory consolidation, problem solving, 
or random brain activity. This belief appears to lead people to 
attribute more importance to dream content than to similar thought 
content that occurs while they are awake. In one study in the paper, 
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.
Psychology
Freud
It was in his book The Interpretation of Dreams (Die Traumdeutung; literally "dream-interpretation"), first published in 1899 (but dated 1900), that Sigmund Freud first argued that the motivation of all dream content is wish-fulfillment (later in Beyond the Pleasure Principle,
 Freud would discuss dreams which do not appear to be wish-fulfillment),
 and that the instigation of a dream is often to be found in the events 
of the day preceding the dream, which he called the "day residue." In 
the case of very young children, Freud claimed, this can be easily seen,
 as small children dream quite straightforwardly of the fulfillment of 
wishes that were aroused in them the previous day (the "dream day"). In 
adults, however, the situation is more complicated—since in Freud's 
submission, the dreams of adults have been subjected to distortion, with
 the dream's so-called "manifest content" being a heavily disguised derivative of the "latent dream-thoughts" present in the unconscious.
 As a result of this distortion and disguise, the dream's real 
significance is concealed: dreamers are no more capable of recognizing 
the actual meaning of their dreams than hysterics are able to understand
 the connection and significance of their neurotic symptoms. 
In Freud's original formulation the latent dream-thought was 
described as having been subject to an intra-psychic force referred to 
as "the censor"; in the more refined terminology of his later years, 
however, discussion was in terms of the super-ego and "the work of the ego's
 forces of defense." In waking life, he asserted, these so-called 
"resistances" altogether prevented the repressed wishes of the 
unconscious from entering consciousness; and though these wishes were to
 some extent able to emerge during the lowered state of sleep, the 
resistances were still strong enough to produce "a veil of disguise" 
sufficient to hide their true nature. Freud's view was that dreams are compromises which ensure that sleep is not interrupted: as "a disguised fulfilment of repressed wishes," they succeed in representing wishes as fulfilled which might otherwise disturb and waken the dreamer.
Freud's "classic" early dream analysis is that of "Irma's injection":
 in that dream, a former patient of Freud's complains of pains. The 
dream portrays Freud's colleague giving Irma an unsterile injection.  
Freud provides us with pages of associations to the elements in his 
dream, using it to demonstrate his technique of decoding the latent 
dream thought from the manifest content of the dream. 
Freud described the actual technique of psychoanalytic 
dream-analysis in the following terms, suggesting that the true meaning 
of a dream must be "weeded out" from dream:
You entirely disregard the apparent connections between the elements in the manifest dream and collect the ideas that occur to you in connection with each separate element of the dream by free association according to the psychoanalytic rule of procedure. From this material you arrive at the latent dream-thoughts, just as you arrived at the patient's hidden complexes from his associations to his symptoms and memories... The true meaning of the dream, which has now replaced the manifest content, is always clearly intelligible. [Freud, Five Lectures on Psycho-Analysis (1909); Lecture Three]
Freud listed the distorting operations that he claimed were applied 
to repressed wishes in forming the dream as recollected: it is because 
of these distortions (the so-called "dream-work") that the manifest 
content of the dream differs so greatly from the latent dream thought 
reached through analysis—and it is by reversing these distortions that the latent content is approached.
The operations included:
- Condensation – one dream object stands for several associations and ideas; thus "dreams are brief, meagre and laconic in comparison with the range and wealth of the dream-thoughts."
 - Displacement – a dream object's emotional significance is separated from its real object or content and attached to an entirely different one that does not raise the censor's suspicions.
 - Visualization – a thought is translated to visual images.
 - Symbolism – a symbol replaces an action, person, or idea.
 
To these might be added "secondary elaboration"—the outcome of the 
dreamer's natural tendency to make some sort of "sense" or "story" out 
of the various elements of the manifest content as recollected. (Freud, 
in fact, was wont to stress that it was not merely futile but actually misleading
 to attempt to "explain" one part of the manifest content with reference
 to another part as if the manifest dream somehow constituted some 
unified or coherent conception). 
Freud considered that the experience of anxiety dreams and nightmares
 was the result of failures in the dream-work: rather than contradicting
 the "wish-fulfillment" theory, such phenomena demonstrated how the ego
 reacted to the awareness of repressed wishes that were too powerful and
 insufficiently disguised. Traumatic dreams (where the dream merely 
repeats the traumatic experience) were eventually admitted as exceptions
 to the theory. 
Freud famously described psychoanalytic dream-interpretation as 
"the royal road to a knowledge of the unconscious activities of the 
mind"; he was, however, capable of expressing regret and dissatisfaction
 at the way his ideas on the subject were misrepresented or simply not 
understood:
The assertion that all dreams require a sexual interpretation, against which critics rage so incessantly, occurs nowhere in my Interpretation of Dreams ... and is in obvious contradiction to other views expressed in it.
— Sigmund Freud, The Interpretation of Dreams
On another occasion, he suggested that the individual capable of 
recognizing the distinction between latent and manifest content "will 
probably have gone further in understanding dreams than most readers of 
my Interpretation of Dreams".
Jung
And although not dismissing Freud's model of dream interpretation wholesale, Carl Jung
 believed Freud's notion of dreams as representations of unfulfilled 
wishes to be limited. Jung argued that Freud's procedure of collecting 
associations to a dream would bring insights into the dreamer's mental 
complex—a person's associations to anything will reveal the mental 
complexes, as Jung had shown experimentally—but not necessarily closer to the meaning of the dream. Jung was convinced that the scope of dream interpretation was larger, reflecting the richness and complexity of the entire unconscious, both personal and collective.
 Jung believed the psyche to be a self-regulating organism in which 
conscious attitudes were likely to be compensated for unconsciously 
(within the dream) by their opposites.
 And so the role of dreams is to lead a person to wholeness through what
 Jung calls "a dialogue between ego and the self". The self aspires to 
tell the ego what it does not know, but it should. This dialogue 
involves fresh memories, existing obstacles, and future solutions.
Jung proposed two basic approaches to analyzing dream material: the objective and the subjective.
 In the objective approach, every person in the dream refers to the 
person they are: mother is mother, girlfriend is girlfriend, etc.
 In the subjective approach, every person in the dream represents an 
aspect of the dreamer. Jung argued that the subjective approach is much 
more difficult for the dreamer to accept, but that in most good 
dream-work, the dreamer will come to recognize that the dream characters
 can represent an unacknowledged aspect of the dreamer. Thus, if the 
dreamer is being chased by a crazed killer, the dreamer may come 
eventually to recognize his own homicidal impulses. Gestalt
 therapists extended the subjective approach, claiming that even the 
inanimate objects in a dream can represent aspects of the dreamer. 
Jung believed that archetypes such as the animus, the anima, the shadow
 and others manifested themselves in dreams, as dream symbols or 
figures. Such figures could take the form of an old man, a young maiden 
or a giant spider as the case may be. Each represents an unconscious 
attitude that is largely hidden to the conscious mind. Although an 
integral part of the dreamer's psyche, these manifestations were largely
 autonomous and were perceived by the dreamer to be external personages.
 Acquaintance with the archetypes as manifested by these symbols serve 
to increase one's awareness of unconscious attitudes, integrating 
seemingly disparate parts of the psyche and contributing to the process 
of holistic self-understanding he considered paramount.
Jung believed that material repressed by the conscious mind, 
postulated by Freud to comprise the unconscious, was similar to his own 
concept of the shadow, which in itself is only a small part of the 
unconscious. 
Jung cautioned against blindly ascribing meaning to dream symbols
 without a clear understanding of the client's personal situation. He 
described two approaches to dream symbols: the causal approach and the 
final approach.
 In the causal approach, the symbol is reduced to certain fundamental 
tendencies. Thus, a sword may symbolize a penis, as may a snake. In the 
final approach, the dream interpreter asks, "Why this symbol and not 
another?" Thus, a sword representing a penis is hard, sharp, inanimate, 
and destructive. A snake representing a penis is alive, dangerous, 
perhaps poisonous and slimy. The final approach will tell additional 
things about the dreamer's attitudes.
Technically, Jung recommended stripping the dream of its details 
and presenting the gist of the dream to the dreamer. This was an 
adaptation of a procedure described by Wilhelm Stekel, who recommended thinking of the dream as a newspaper article and writing a headline for it. Harry Stack Sullivan also described a similar process of "dream distillation."
Although Jung acknowledged the universality of archetypal 
symbols, he contrasted this with the concept of a sign—images having a 
one-to-one connotation with their meaning. His approach was to recognize
 the dynamism and fluidity that existed between symbols and their 
ascribed meaning. Symbols must be explored for their personal 
significance to the patient, instead of having the dream conform to some
 predetermined idea. This prevents dream analysis from devolving into a 
theoretical and dogmatic exercise that is far removed from the patient's
 own psychological state. In the service of this idea, he stressed the 
importance of "sticking to the image"—exploring in depth a client's 
association with a particular image. This may be contrasted with Freud's
 free associating which he believed was a deviation from the salience of
 the image. He describes for example the image "deal table." One would 
expect the dreamer to have some associations with this image, and the 
professed lack of any perceived significance or familiarity whatsoever 
should make one suspicious. Jung would ask a patient to imagine the 
image as vividly as possible and to explain it to him as if he had no 
idea as to what a "deal table" was. Jung stressed the importance of 
context in dream analysis.
Jung stressed that the dream was not merely a devious puzzle invented by the unconscious to be deciphered, so that the true
 causal factors behind it may be elicited. Dreams were not to serve as 
lie detectors, with which to reveal the insincerity behind conscious 
thought processes. Dreams, like the unconscious, had their own language.
 As representations of the unconscious, dream images have their own 
primacy and mechanics. 
Jung believed that dreams may contain ineluctable truths, 
philosophical pronouncements, illusions, wild fantasies, memories, 
plans, irrational experiences and even telepathic visions.
 Just as the psyche has a diurnal side which we experience as conscious 
life, it has an unconscious nocturnal side which we apprehend as 
dreamlike fantasy. Jung would argue that just as we do not doubt the 
importance of our conscious experience, then we ought not to second 
guess the value of our unconscious lives.
Hall
In 1953, Calvin S. Hall developed a theory of dreams in which dreaming is considered to be a cognitive process.
 Hall argued that a dream was simply a thought or sequence of thoughts 
that occurred during sleep, and that dream images are visual 
representations of personal conceptions. For example, if one dreams of 
being attacked by friends, this may be a manifestation of fear of 
friendship; a more complicated example, which requires a cultural 
metaphor, is that a cat within a dream symbolizes a need to use one's 
intuition. For English
 speakers, it may suggest that the dreamer must recognize that there is 
"more than one way to skin a cat," or in other words, more than one way 
to do something.
Faraday, Clift, et al.
In the 1970s, Ann Faraday
 and others helped bring dream interpretation into the mainstream by 
publishing books on do-it-yourself dream interpretation and forming 
groups to share and analyze dreams. Faraday focused on the application 
of dreams to situations occurring in one's life. For instance, some 
dreams are warnings of something about to happen—e.g. a dream of failing
 an examination, if one is a student, may be a literal warning of 
unpreparedness. Outside of such context, it could relate to failing some
 other kind of test. Or it could even have a "punny" nature, e.g. that one has failed to examine some aspect of his life adequately. 
Faraday noted that "one finding has emerged pretty firmly from 
modern research, namely that the majority of dreams seem in some way to 
reflect things that have preoccupied our minds during the previous day 
or two."
In the 1980s and 1990s, Wallace Clift and Jean Dalby Clift
 further explored the relationship between images produced in dreams and
 the dreamer's waking life. Their books identified patterns in dreaming,
 and ways of analyzing dreams to explore life changes, with particular 
emphasis on moving toward healing and wholeness.