Analytical psychology (German: Analytische Psychologie, sometimes translated as analytic psychology and referred to as Jungian analysis) is the name Carl Jung, a Swiss psychiatrist, gave to his new "empirical science" of the psyche to distinguish it from Freud's psychoanalytic theories as their seven year collaboration on psychoanalysis was drawing to an end between 1912 and 1913. The evolution of his science is contained in his monumental opus, the Collected Works, written over sixty years of his lifetime.Among widely used concepts owed specifically to Analytical psychology are: anima and animus, archetypes, the collective unconscious, complexes, extraversion and introversion, individuation, the Self, the shadow and synchronicity. The Myers–Briggs Type Indicator (MBTI) is based on another of Jung's theories on psychological types. A less well known idea was Jung's notion of the Psychoid to denote a hypothesised immanent plane beyond consciousness, distinct from the collective unconscious, and a potential locus of synchronicity.The approximately "three schools" of post-Jungian analytical psychology that are current, the classical, archetypal and developmental, can be said to correspond to the developing yet overlapping aspects of Jung's lifelong explorations, even if he expressly did not want to start a school of "Jungians".(pp. 50–53) Hence as Jung proceeded from a clinical practice which was mainly traditionally science-based and steeped in rationalist philosophy, his enquiring mind simultaneously took him into more esoteric spheres such as alchemy, astrology, Gnosticism, metaphysics, the occult and the paranormal, without ever abandoning his allegiance to science as his long lasting collaboration with Wolfgang Pauli attests. His wide ranging progression suggests to some commentators that, over time, his analytical psychotherapy, informed by his intuition and teleological investigations, became more of an "art".