Carl Jung's theory of the collective unconscious posits the existence of a deeper layer of the psyche, distinct from the personal unconscious. This collective unconscious is not individual but universal, possessing contents and modes of behavior that are more or less the same across all individuals. It constitutes a common psychic substrate of a suprapersonal nature present in every human being. According to Jung, the collective unconscious does not owe its existence to personal experience and is not a personal acquisition but is inborn and inherited. In contrast, the personal unconscious consists mainly of contents that were once conscious but have been forgotten or repressed, as well as feeling-toned complexes that constitute the personal and private side of psychic life. Jung argued that while Freud limited the unconscious to repressed or forgotten personal contents, he recognized its archaic and mythological thought-forms, which Jung developed further into the concept of the collective unconscious. The content of the collective unconscious is made up essentially of archetypes. Jung adopted the term "archetype," which has historical roots, to indicate the existence of definite forms in the psyche that appear to be present always and everywhere. Mythological research refers to these as "motifs," and in the psychology of primitives, they correspond to Lévy-Bruhl's "représentations collectives," while comparative religion defines them as "categories of the imagination". Adolf Bastian called them "elementary" or "primordial thoughts". Jung defined an archetype literally as a pre-existent form. He clarified that archetypes are not inherited ideas but rather inherited possibilities of ideas, or predispositions to react in certain ways. The term "image" in relation to archetypes is intended to express not only the form of the activity taking place but also the typical situation in which the activity is released, often the encounter between a collective member and the collective. Jung saw archetypes as the unconscious images of the instincts themselves, suggesting that they are patterns of instinctual behavior. These archetypes manifest in various forms, such as mythological types, symbols in dreams, art, religion, and rituals. Examples of well-known archetypes include the animus/anima (the archetypal image a woman has of man and vice versa), the shadow (the repressed or denied aspects of the personality), and the Great Mother (an archetype of maternal love and birth). The androgyne, possessing sex characteristics of both genders, also holds a central position in Jung's theory as representing the resolution of sexual difference. Myths, according to Jung, are metaphors or dramatizations of the inner workings of the archetypes within the collective unconscious, revealing the structure of the pre-conscious psyche. Jung's theory of the collective unconscious stands in contrast to Freud's focus on the personal unconscious shaped by individual experiences and repression. While Freud attributed the unconscious to repression, Jung accounted for the appearance of apparently ancient symbols in dreams without personal experience by suggesting a supra-personal, collective unconscious. He saw the collective unconscious as the source of religious experience and creative impulses, a living system of reactions and aptitudes inherited from humanity's remotest beginnings. The concept of individuation, a central aspect of Jung's developmental psychology, involves a lifelong confrontation between the self and the unconscious, the domain of the archetypes. Through this process, individuals aim to realize their unique selfhood by integrating the contents of the unconscious, including the archetypes. Projection, a common psychic phenomenon, involves attributing unconscious contents to others. Recognizing and withdrawing projections is crucial for individuation, requiring engagement with unconscious contents revealed in dreams and active imagination. Some critical theorists have offered alternative perspectives on Jung's ideas. For instance, Eugène Minkowski considered Jung's concept of the collective unconscious to be an unfortunate relapse into spiritualism [Source not provided in excerpts]. Ludwig Binswanger regarded it as a biologistic mythology [Source not provided in excerpts]. Medard Boss, who had a working relationship with Jung, criticized the concept of the archetype and the collective unconscious as a psychologized neo-Platonist metaphysics, a mere abstraction of thought that does not appear in everyday experience. From a Marxist perspective, Jameson views Freudian psychoanalysis as historically determined by capitalism, suggesting that the concept of a timeless "human psyche" is an illusion, and proposes the doctrine of a "political unconscious" which is distinct from Jung's collective unconscious. Frances Gray also critiques Jung's idea of individuation as limited by masculine assumptions intrinsic to his figuring of the collective unconscious. Regarding the knowability of the collective unconscious, Jung himself stated that what we mean by "archetype" is in itself irrepresentable, but has effects that make visualizations possible. He also noted that the unconscious is unknown, making assimilation challenging. However, aspects of the unconscious become known through dreams and experiences, suggesting it is not entirely unknowable. Gray argues that if the collective unconscious is accepted as unknown, then sex/gender or any other predications cannot be definitively made about it. Despite this, Jung's work seems to figure unconsciousness as feminine at times. In summary, Carl Jung's theory of the collective unconscious describes an inherited, universal layer of the psyche containing archetypes, which are primordial patterns and images that shape human experience and are manifested in myths, symbols, dreams, and other cultural expressions. This concept is central to Jung's understanding of the psyche, its development through individuation, and its connection to the shared history and potential of humanity.