At a simple and informal level, the notion of an unconscious mind (or subconscious) would seem a usefully straightforward way of accounting for aspects of the mind of which we are not directly conscious or aware. Upon deeper examination, however, the topic reveals extraordinary complexity.

So many different ideas and theories have been advanced through the ages, and so widely have these various kinds of 'unconscious mind' differed from each other, that one might easily sympathise with behaviourism's decision to study merely patterns of 'stimulus and response' without engaging in speculation about conscious and unconscious mental states! At the present stage, there are still fundamental disagreements within psychology about what the nature of the 'unconscious mind' might be (if indeed it is considered to exist at all) -- whereas outside formal psychology a whole world of pop-psychological speculation has grown up in which the 'unconscious mind' is held to have any number of properties and abilities from the animalistic and infantile, through the innocent and child-like, to the savant-like, all-perceiving, mystical and occult.

Probably the most detailed and precise of the various notions of 'unconscious mind' - and the one which most people will immediately think of upon hearing the term - is that developed by Sigmund Freud and his followers, and which lies at the heart of psychoanalysis. (It should be stressed, incidentally, that the popular term 'subconscious' is not a Freudian coinage and is never used in serious psychoanalytic writings).

Freud's concept was a more subtle and complex psychological theory than many. Consciousness, in Freud's topographical view (which was his first of several psychological models of the mind) was a relatively thin perceptual aspect of the mind, whereas the subconscious (frequently misused and confused with the unconscious) was that merely autonomic function of the brain. The unconscious was indeed considered by Freud throughout the evolution of his psychoanalytic theory a sentient force of will influenced by human drives and yet operating well below the perceptual conscious mind. Hidden, like the man behind the curtain in the "Wizard of Oz," the unconscious directs the thoughts and feelings of everyone, according to Freud. This unconscious mind is the primitive instinctual hangover we all suffer from and which we must overcome in a healthy way in order to become fully and normally developed, i.e., not neurotic or psychotic but merely unhappy (See Frank Sulloway's "Freud, Biologist of the Mind," Basic Books, 1983).

History:

The idea originated in antiquity, and its more modern history is detailed in Henri F Ellenberger's Discovery of the Unconscious (Basic Books, 1970).

Certain philosophers preceding Sigmund Freud such as Leibniz and Schopenhauer developed ideas foreshadowing the subconscious. The new medical science of psychoanalysis established by Freud and his disciples popularized this and similar notions such as the role of the libido (sex drive) and the self-destructive urge of thanatos (death wish), and the famous Oedipus complex wherein a son seeks to "kill" his father to make love to his own mother.

The term was popularized by Freud. He developed the idea that there were layers to human consciousness: the conscious, preconscious, and unconscious. He thought that certain psychic events take place "below the surface", or in the unconscious mind. A good example is dreaming, which Freud called the "royal road to the unconscious".

In another of Freud's systematizations, the mind is divided into the Conscious mind or Ego and two parts of the Unconscious: the Id or instincts and the Superego. Freud used the idea of the unconscious in order to explain certain kinds of neurotic behavior
(See psychoanalysis).

Carl Jung developed the concept further. He divided the unconscious into two parts: the personal unconscious and the collective unconscious. The first of these corresponds to Freud's idea of the subconscious, though unlike his mentor, Jung believed that the personal unconscious contained a valuable counter-balance to the conscious mind, as well as childish urges. As for the collective unconscious, which consists of archetypes, this is the common store of mental building blocks that makes up the psyche of all humans. Evidence for its existence is the universality of certain symbols that appear in the mythologies of nearly all peoples.

There are other views. Jane Roberts (in the Seth books) presents a rich portrait of consciousness in which the unconscious mind is described as being clairvoyant and in communication with all other minds. The self that each of us experiences day-to-day is described as being but one facet of a richer and very complex multi-dimensional entity.

Read more about:

• Controversies and Questions ABOUT UNCONSCIOUS MIND
• Terminology and Unconscious MENTAL PROCESSES