Carl Jung in the context of "Depth psychology"

Psychoanalysis is a set of theories and techniques of research to discover unconscious processes and their influence on conscious thought, emotion and behavior. Based on dream interpretation, psychoanalysis is also a talk therapy method for treating mental disorders. Established in the early 1890s by Sigmund Freud, it takes into account Darwin's theory of evolution, neurology findings, ethnology reports, and, in some respects, the clinical research of his mentor Josef Breuer. Freud developed and refined the theory and practice of psychoanalysis until his death in 1939. In an encyclopedic article, he identified its four cornerstones: "the assumption that there are unconscious mental processes, the recognition of the theory of repression and resistance, the appreciation of the importance of sexuality and of the Oedipus complex."

Freud's earlier colleagues Alfred Adler and Carl Jung soon developed their own methods (individual and analytical psychology); he criticized these concepts, stating that they were not forms of psychoanalysis. After the author's death, neo-Freudian thinkers like Erich Fromm, Karen Horney and Harry Stack Sullivan created some subfields. Jacques Lacan, whose work is often referred to as Return to Freud, described his metapsychology as a technical elaboration of the three-instance model of the psyche and examined the language-like structure of the unconscious.

Numinous (/ˈnjuːmɪnəs/) means "arousing spiritual or religious emotion; mysterious or awe-inspiring"; also "supernatural" or "appealing to the aesthetic sensibility." The term was given its present sense by the German theologian and philosopher Rudolf Otto in his influential 1917 German book The Idea of the Holy. He also used the phrase mysterium tremendum as another description for the phenomenon. Otto's concept of the numinous influenced thinkers including Carl Jung, Mircea Eliade, and C. S. Lewis. It has been applied to theology, psychology, religious studies, literary analysis, and descriptions of psychedelic experiences.

A triple deity is a deity with three apparent forms that function as a singular whole. Such deities may sometimes be referred to as threefold, tripled, triplicate, tripartite, triune, triadic, or as a trinity. The number three has a long history of mythical associations and triple deities are common throughout world mythology. Carl Jung considered the arrangement of deities into triplets an archetype in the history of religion.

In classical religious traditions, three separate beings may represent either a triad who typically appear as a group (the Greek Moirai, the Roman Parcae, the Norse Norns, the Baltic Dēkla, Kārta and Laima, or the Irish Badb, Macha and Morrígan), or a single deity notable for having three aspects (Greek Hecate and Islamic Hermes Trismegistus). Trinitarian Christianity instead recognizes three "divine persons" in God the Father, the Son, and the Holy Spirit, which are usually distinguished from the idea of independent gods or aspects.

Adult development encompasses the changes that occur in biological and psychological domains of human life from the end of adolescence until the end of one's life. Changes occur at the cellular level and are partially explained by biological theories of adult development and aging. Biological changes influence psychological and interpersonal/social developmental changes, which are often described by stage theories of human development. Stage theories typically focus on "age-appropriate" developmental tasks to be achieved at each stage. Erik Erikson and Carl Jung proposed stage theories of human development that encompass the entire life span, and emphasized the potential for positive change very late in life.

The concept of adulthood has legal and socio-cultural definitions. The legal definition of an adult is a person who is fully grown or developed. This is referred to as the age of majority, which is age 18 in most cultures, although there is a variation from 15 to 21. The typical perception of adulthood is that it starts at age 18, 21, 25 or beyond. Middle-aged adulthood, starts at about age 40, followed by old age/late adulthood around age 65. The socio-cultural definition of being an adult is based on what a culture normatively views as being the required criteria for adulthood, which in turn, influences the lives of individuals within that culture. This may or may not coincide with the legal definition. Current views on adult development in late life focus on the concept of successful aging, defined as "...low probability of disease and disease-related disability, high cognitive and physical functional capacity, and active engagement with life."

Analytical psychology (German: analytische Psychologie, sometimes translated as analytic psychology; also Jungian analysis) is a term referring to the psychological practices of Carl Jung. It was designed 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.

The history of analytical psychology is intimately linked with the biography of Jung. At the start, it was known as the "Zurich school", whose chief figures were Eugen Bleuler, Franz Riklin, Alphonse Maeder and Jung, all centred in the Burghölzli hospital in Zurich. It was initially a theory concerning psychological complexes until Jung, upon breaking with Sigmund Freud, turned it into a generalised method of investigating archetypes and the unconscious, as well as into a specialised psychotherapy.

Extraversion and introversion are a central trait dimension in human personality theory. The terms were introduced into psychology by Carl Jung, though both the popular understanding and current psychological usage are not the same as Jung's original concept. Extraversion (also spelled extroversion) is typically associated with sociability, talkativeness, and high energy, while introversion is linked to introspection, reserve, and a preference for solitary activities. Jung defined introversion as an "attitude-type characterised by orientation in life through subjective psychic contents", and extraversion as "an attitude-type characterised by concentration of interest on the external object".

While often presented as opposite ends of a single continuum, many personality theorists, such as Carl Jung, have suggested that most individuals possesses elements of both traits, with one being more dominant. Virtually all comprehensive models of personality include these concepts in various forms. Examples include the Big Five model, Jung's analytical psychology, Hans Eysenck's three-factor model, Raymond Cattell's 16 personality factors, the Minnesota Multiphasic Personality Inventory, and the Myers–Briggs Type Indicator.