In the 21st century, Carl Gustav Jung (1875-1961) remains one of the key figures in the field of analytical psychology - and Psychological Types, or The Psychology of Individuation, published in 1921, is one of his most influential works. It was written during the decade after the publication of Psychology of the Unconscious (1912), which effectively ended his friendship and collaboration with Sigmund Freud.

The Red Book, published to wide acclaim in 2009, contains the nucleus of C. G. Jung's later works. It was here that he developed his principal theories of the archetypes, the collective unconscious, and the process of individuation that would transform psychotherapy from treatment of the sick into a means for the higher development of the personality.

In 1957, four years before his death, Carl Gustav Jung, psychiatrist and psychologist, began writing his life story. But what started as an exercise in autobiography soon morphed into an altogether more profound undertaking. The result is an absorbing piece of self-analysis: a frank statement of faith, philosophy, and principles from one of the great explorers of the human mind.

Jung's discovery of the 'collective unconscious', a psychic inheritance common to all humankind, transformed the understanding of the self and the way we interpret the world. In On the Nature of the Psyche Jung describes this remarkable theory in his own words, and presents a masterly overview of his theories of the unconscious, and its relation to the conscious mind. Also contained in this collection is On Psychic Energy, where Jung defends his interpretation of the libido, a key factor in the breakdown of his relations with Freud. 

Published first in 1912, Psychology of the Unconscious was one of the most important stepping stones in the development of Jung’s thought and practice. It has a long subtitle: A Study of the Transformations and Symbolisms of the Libido. A Contribution to the History of the Evolution of Thought. This expressed the underlying impetus - a break from the view of the libido and its functions as taught by Sigmund Freud, which Jung had earlier adopted. It was from this point that the two approaches, which came to be known as the Swiss and Viennese schools, emerged.