The unconscious mind (or the unconscious) consists of the processes in the mind that occur automatically and are not available to introspection, and include thought processes, memory, affect, and motivation.^[1] The term unconscious mind was coined by the 18th century German romantic philosopher Friedrich Schelling and later introduced into English by the poet and essayist Samuel Taylor Coleridge. The concept was developed and popularized by the Austrian neurologist and psychoanalyst Sigmund Freud. Empirical evidence suggests that unconscious phenomena include repressed feelings, automatic skills, subliminal perceptions, thoughts, habits, and automatic reactions,^[1] and possibly also complexes, hidden phobias and desires. In psychoanalytic theory, unconscious processes are understood to be expressed in dreams in a symbolical form, as well as in slips of the tongue and jokes. Thus the unconscious mind can be seen as the source of dreams and automatic thoughts (those that appear without any apparent cause), the repository of forgotten memories (that may still be accessible to consciousness at some later time), and the locus of implicit knowledge (the things that we have learned so well that we do them without thinking).

It has been argued that consciousness is influenced by other parts of the mind. These include unconsciousness as a personal habit, being unaware, and intuition. Terms related to semi-consciousness include: awakening, implicit memory, subliminal messages, trances, hypnagogia, and hypnosis. While sleep, sleep walking, dreaming, delirium, and comas may signal the presence of unconscious processes, these processes are not the unconscious mind itself, but rather symptoms.

Some critics have doubted the existence of the unconscious.^[2][3][4]

The term unconscious mind was coined by the 18th century German romantic philosopher Friedrich Schelling and later introduced into English by the poet and essayist Samuel Taylor Coleridge.^[5]

Articulating the idea of something not conscious, or, actively denied to awareness, with the constructs of language has been a process of human thought and interpersonal influence for millennia. For example, influences on thinking that originate from outside of an individual's consciousness were reflected in the ancient ideas of temptation, divine inspiration, and the predominant role of the gods in affecting motives and actions. The idea of internalised unconscious processes in the mind was also instigated in antiquity^[6] and has been explored across a wide variety of cultures. Unconscious aspects of mentality were referred to between 2500 and 600 BC in the Hindu texts known as the Vedas, found today in Ayurvedic medicine.^{[7][8][9][10]}

Paracelsus is credited as the first to make mention of an unconscious aspect of cognition in his work Von den Krankheiten (translates as "About illnesses", 1567), and his clinical methodology created a cogent system that is regarded by some as the beginning of modern scientific psychology.^[11] William Shakespeare explored the role of the unconscious^[12] in many of his plays, without naming it as such.^[13][14][15] In addition, Western philosophers such as Baruch Spinoza, Gottfried Leibniz, Arthur Schopenhauer, Søren Kierkegaard, and Friedrich Nietzsche, developed a western view of the mind which foreshadowed Freud's theories. Psychologist Jacques Van Rillaer points out that, "the unconscious was not discovered by Freud. In 1890, when psychoanalysis was still unheard of, William James, in his monumental treatise on psychology, examined the way Schopenhauer, von Hartmann, Janet, Binet and others had used the term 'unconscious' and 'subconscious'".^[16] Historian of psychology Mark Altschule observes that, "It is difficult—or perhaps impossible—to find a nineteenth-century psychologist or psychiatrist who did not recognize unconscious cerebration as not only real but of the highest importance."^[17]

Some neuroscientific research supports the existence of the unconscious mind.^[18] For example, researchers at Columbia University Medical Center have found that fleeting images of fearful faces—images that appear and disappear so quickly that they escape conscious awareness—produce unconscious anxiety that can be detected in the brain with the latest neuroimaging machines.^[19] The conscious mind is thus hundreds of milliseconds slower than unconscious processes.

To understand this type of research, a distinction has to be made^{[citation needed]} between unconscious processes and the unconscious mind (neuroscientists^[who?] are far more likely to examine the former^{[citation needed]}). The unconscious mind and its expected psychoanalytic contents^{[20][21][22][23][24][25]} also differ from unconsciousness, coma, and a minimally conscious state. The difference in the uses of the terms can be explained, to a degree, by our different hypotheses on its subject. One such conjecture^{[editorializing]} is the psychoanalytic theory.^[26]

Sigmund Freud and his followers developed an account of the unconscious mind. It plays an important role in psychoanalysis.

Freud divided the mind into the conscious mind (or the ego) and the unconscious mind. The latter was then further divided into the id (or instincts and drive) and the superego (or conscience). In this theory, the unconscious refers to the mental processes of which individuals make themselves unaware.^[27] Freud proposed a vertical and hierarchical architecture of human consciousness: the conscious mind, the preconscious, and the unconscious mind—each lying beneath the other. He believed that significant psychic events take place "below the surface" in the unconscious mind,^[28] like hidden messages from the unconscious. He interpreted such events as having both symbolic and actual significance.

In psychoanalytic terms, the unconscious does not include all that is not conscious, but rather what is actively repressed from conscious thought or what a person is averse to knowing consciously. Freud viewed the unconscious as a repository for socially unacceptable ideas, wishes or desires, traumatic memories, and painful emotions put out of mind by the mechanism of psychological repression. However, the contents did not necessarily have to be solely negative. In the psychoanalytic view, the unconscious is a force that can only be recognized by its effects—it expresses itself in the symptom. In a sense, this view places the conscious self as an adversary to its unconscious, warring to keep the unconscious hidden. Unconscious thoughts are not directly accessible to ordinary introspection, but are supposed to be capable of being "tapped" and "interpreted" by special methods and techniques such as meditation, free association (a method largely introduced by Freud), dream analysis, and verbal slips (commonly known as a Freudian slip), examined and conducted during psychoanalysis. Seeing as these unconscious thoughts are normally cryptic, psychoanalysts are considered experts in interpreting their messages.

Freud later used his notion of the unconscious in order to explain certain kinds of neurotic behavior. Nevertheless, Freud's theory of the unconscious was substantially transformed by some of his followers, among them Carl Jung and Jacques Lacan.

Carl Gustav Jung, a Swiss psychiatrist, developed the concept further. He divided the unconscious into two parts: the personal unconscious and the collective unconscious. The personal unconscious is a reservoir of material that was once conscious but has been forgotten or suppressed, much like the typical notion of the unconscious to Freud. The collective unconscious, however, is the deepest level of the psyche, containing the accumulation of inherited psychic structures and archetypal experiences. The collective unconscious is therefore said to be inherited and contain material of an entire species rather than of an individual.^[29] In addition to the structure of the unconscious, Jung differed from Freud in that he did not believe that sexuality was at the base of all unconscious thoughts.^[30]

There are still fundamental disagreements within psychology about the nature of the unconscious mind. There is controversy as to the scientific validity of the concept of the unconscious, and whether the unconscious mind exists at all has been disputed.

Franz Brentano rejected the concept of the unconscious in his 1874 book Psychology from an Empirical Standpoint, although his rejection followed largely from his definitions of consciousness and unconsciousness.^[31]

Jean-Paul Sartre offers a critique of Freud's theory of the unconscious in Being and Nothingness, based on the claim that consciousness is essentially self-conscious. Sartre also argues that Freud's theory of repression is internally flawed. Philosopher Thomas Baldwin argues that Sartre's argument is based on a misunderstanding of Freud.^[2]

Erich Fromm contends that, "The term 'the unconscious' is actually a mystification (even though one might use it for reasons of convenience, as I am guilty of doing in these pages). There is no such thing as the unconscious; there are only experiences of which we are aware, and others of which we are not aware, that is, of which we are unconscious. If I hate a man because I am afraid of him, and if I am aware of my hate but not of my fear, we may say that my hate is conscious and that my fear is unconscious; still my fear does not lie in that mysterious place: 'the' unconscious."^[32]

John Searle has offered a critique of the Freudian unconscious. He contends that the very notion of a collection of "thoughts" that exist in a privileged region of the mind such that they are in principle never accessible to conscious awareness, is incoherent. This is not to imply that there are not "nonconscious" processes that form the basis of much of conscious life. Rather, Searle simply claims that to posit the existence of something that is like a "thought" in every way except for the fact that no one can ever be aware of it (can never, indeed, "think" it) is an incoherent concept. To speak of "something" as a "thought" either implies that it is being thought by a thinker or that it could be thought by a thinker. Processes that are not causally related to the phenomenon called thinking are more appropriately called the nonconscious processes of the brain.^[33]

Other critics of the Freudian unconscious are David Stannard,^[3] Richard Webster,^[4] and Ethan Watters and Richard Ofshe.^[34]

David Holmes^[35] examined sixty years of research about the Freudian concept of "repression", and concluded that there is no positive evidence for this concept. Given the lack of evidence of many Freudian hypotheses, some scientific researchers proposed the existence of unconscious mechanisms that are very different from the Freudian ones. They speak of a "cognitive unconscious" (John Kihlstrom),^[36][37] an "adaptive unconscious" (Timothy Wilson),^[38] or a "dumb unconscious" (Loftus & Klinger),^[39] which executes automatic processes but lacks the complex mechanisms of repression and symbolic return of the repressed.

In modern cognitive psychology, many researchers have sought to strip the notion of the unconscious from its Freudian heritage, and alternative terms such as "implicit" or "automatic" have come into currency. These traditions emphasize the degree to which cognitive processing happens outside the scope of cognitive awareness, and show that things we are unaware of can nonetheless influence other cognitive processes as well as behavior.^{[40][41][42][43][44]} Active research traditions related to the unconscious include implicit memory (see priming, implicit attitudes), and nonconscious acquisition of knowledge (see Lewicki, see also the section on cognitive perspective, below).

While, historically, the psychoanalytic research tradition was the first to focus on the phenomenon of unconscious mental activity, there is an extensive body of conclusive research and knowledge in contemporary cognitive psychology devoted to the mental activity that is not mediated by conscious awareness.

Most of that (cognitive) research on unconscious processes has been done in the mainstream, academic tradition of the information processing paradigm. As opposed to the psychoanalytic tradition, driven by the relatively speculative (in the sense of being hard to empirically verify), theoretical concepts such as the Oedipus complex or Electra complex, the cognitive tradition of research on unconscious processes is based on relatively few theoretical assumptions and is very empirically oriented (i.e., it is mostly data driven). Cognitive research has revealed that automatically, and clearly outside of conscious awareness, individuals register and acquire more information than what they can experience through their conscious thoughts. (See Augusto, 2010, for a recent comprehensive survey.)^[45]

For example, an extensive line of research conducted by Hasher and Zacks^[46] has demonstrated that individuals register information about the frequency of events automatically (i.e., outside of conscious awareness and without engaging conscious information processing resources). Moreover, perceivers do this unintentionally, truly "automatically," regardless of the instructions they receive, and regardless of the information processing goals they have. Interestingly, the ability to unconsciously and relatively accurately tally the frequency of events appears to have little or no relation to the individual's age,^[47] education, intelligence, or personality, thus it may represent one of the fundamental building blocks of human orientation in the environment and possibly the acquisition of procedural knowledge and experience, in general.

• Adaptive unconscious
• Consciousness
• Introspection illusion
• Mind's eye
• Neuroscience of free will
• Preconscious
• Transpersonal psychology
• Unconscious cognition
• Unconscious communication

Transdisciplinary topics

• Cell signaling
• Molecular Cellular Cognition
• Philosophy of mind
• Portal:thinking
• List of thought processes

Books

• Psyche
• The Philosophy of the Unconscious

• [4]^{[dead link‍]} from Dictionary of Philosophy of Mind, "Implicit Memory"
• Nonconscious Acquisition of Information (a reprint from American Psychologist, 1992)

• Logic & the Unconscious Mind (An international research project on the relations between unconscious mentation and logic)
• The Rediscovery of the Unconscious
• Nonconscious Acquisition of Information (a reprint from American Psychologist, 1992)