Black’s Medical Dictionary (39th edition) defines the unconscious as “a description of mental activities of which an individual is unaware” (p. 567).
In the West, the idea of the unconscious has an interesting history. It’s found in the ancient Greek literature of Sophocles, with related ideas like hubris, and in Shakespeare and more recent luminaries like James Joyce.
Philosophical debates about its character flourished in the 18th century among thinkers like John Locke and David Hume. In the 20th century, Freud, Pierre Janet, Alfred Adler, Carl Jung and many others presented their unique theories about the unconscious.
Arthur Koestler believes the idea of the unconscious was already known before the actual word was coined. Koestler cites several examples where the notion of the unconscious is implied in the arts and philosophy (e.g. Dante, Kepler and Kant). Koestler also says that consciousness and unconsciousness are not discrete states but exist along a continuum.¹
From Koestler it seems reasonable to suggest that the range and character of this experiential continuum varies among individuals. In other words, some people access different types of thoughts and emotions than others.
But we should remember that the unconscious is just a concept. All too often it’s reified. Reification means ideas are assumed to represent some real entity or thing–for instance, the sociological idea of “the state.” Reified concepts may even point to detailed legal entities.²
A common misunderstanding among contemporary writers is to say that Freud sees the unconscious as uniquely personal while his former protege Carl Jung sees it as collective.³ In fact, both theorist recognize personal and collective aspects within their respective theories of the unconscious.
¹ Koestler, Arthur. The Act of Creation. New York: Penguin [Arkana], 1989: 147-177.
² Reification is also a concept. So the question remains as to whether the thing written or talked about actually exists as described.