The unconscious mind (or the unconscious) consists of the processes in the mind which occur automatically and are not available to introspection and include thought processes, memories, interests, and motivations.
Even though these processes exist well under the surface of conscious awareness, they are theorized to exert an effect on behavior. The term was coined by the 18th-century German Romantic philosopher Friedrich Schelling and later introduced into English by the poet and essayist Samuel Taylor Coleridge.
Empirical evidence suggests that unconscious phenomena include repressed feelings, automatic skills, subliminal perceptions, and automatic reactions, and possibly also complexes, hidden phobias, and desires.
The concept was popularized by the Austrian neurologist and psychoanalyst Sigmund Freud. In psychoanalytic theory, unconscious processes are understood to be directly represented in dreams, 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. Phenomena related to semi-consciousness include awakening, implicit memory, subliminal messages, trances, hypnagogia and hypnosis. While sleep, sleepwalking, dreaming, delirium and comas may signal the presence of unconscious processes, these processes are seen as symptoms rather than the unconscious mind itself.