The personal unconsciousness is the repository of one's day-to-day experiences. Whether remembered or forgotten, all our emotions and feelings are held here.

The collective unconsciousness, however, is not particular to any single individual, but is shared in common by the whole of mankind. It contains the memories of our ancestors, a record of the collective experiences of humanity. This includes concepts, ideas and ways of thinking and reacting to the world. It is common to all peoples, independent of historical or cultural tradition, and is known by some as the Wisdom of the Ages, by others as the Race Memory.

Jung considered that contacting the collective unconsciousness played an important part in one's self-development. In his therapies he examined the imagery of dreams. Beneath the surface gloss, which related to the dreamer's personal unconsciousness (see the Minor Arcana), he found that the deeper levels could be uncovered. These related to the collective unconsciousness. By contact with the collective unconsciousness the dreamer has access to the knowledge acquired by mankind over millennia. The collective unconsciousness uses a language of images known as archetypes. The archetypes appear in personified or symbolic picture form. They are cross-cultural and may be recognized in all mythologies, fairie tales and religious traditions (myths describe psychic processes in a highly symbolic form). Archetypes are the basic forces of the universe, and represent typical fundamental experiences. As the basic building blocks of experience they are of necessity limited in number, but when combined, the archetypes represent the sum total of the inherent potential of the human psyche. This is a huge inexhaustible treasure house of ancient knowledge dealing with the most profound relations between man and the cosmos.