The collective unconscious refers to that part of a person's unconscious which is common to all human beings. It contains archetypes, which are forms or symbols that are manifested by all people in all cultures. They are said to exist prior to experience, and are in this sense instinctual. Critics have argued that this is an ethnocentrist view, which universalized Jung's European-styled archetypes into human beings' archetypes.

Less mystical proponents of the Jungian model hold that the collective unconscious can be adequately explained as arising in each individual from shared instinct, common experience, and shared culture. The natural process of generalization in the human mind combines these common traits and experiences into a mostly identical substratum of the unconscious

For Jung then, the Collective Unconscious is not, as many of his popularisers claim, a kind of "Universal Mind" or metaphysical reality, like the Platonic World of Forms, but rather an ultimately biological reality. The Spiritual concepts of Platonism are not seen as metaphysical, but biological, or rather, psycho-biological. The Jungian schema can thus be represented as follows:

Everyone has their own Personal Unconscious. The Collective Unconscious in contrast is universal. It cannot be built up like one's personal unconscious is; rather, it predates the individual. It is the repositary of all the religious, spiritual, and mythological symbols and experiences. Its primary structures - the deep structures of the psyche, in other words.

Jung called "Archetypes"; a later-Hellenistic Platonic and Augustinian Christian term that referred to the spiritual forms which are the pre-existent prototypes of the things of the material world. Interpreting this idea psychologically, Jung stated that these archetypes were the conceptual matrixes or patterns behind all our religious and mythological concepts, and indeed, our thinking processes in general.