Final answer:
Carl Jung, the Swiss psychiatrist, is the theorist known for the concept of collective consciousness, which he referred to as the collective unconscious. This concept suggests that there are universal archetypal themes and symbols, inherited through our psyche, that are shared among all human beings.
Step-by-step explanation:
The theorist who believed in the concept of the collective consciousness was the Swiss psychiatrist Carl Jung. Jung proposed that the collective unconscious is a universal form of the personal unconscious, housing mental patterns or memory traces common to all humans. According to Jung, these ancestral memories, referred to as archetypes, are expressed through universal themes found in literature, art, and dreams, and mirror the shared experiences of humans, such as dealing with death, seeking independence, and the pursuit for mastery.
Jung's identification of universal symbolic figures like the hero, the maiden, the sage, and the trickster in folklore across various cultures speaks to the existence of a shared psychological heritage. Unlike Sigmund Freud, who posited that personality is shaped by past events alone, Jung incorporated the future orientation and self-actualization into his theories, focusing on the process of integrating these unconscious archetypal elements for self-realization.
The idea of the collective unconscious not only enriched psychological theory but also influenced other disciplines, including sociology and anthropology, signifying the interconnectedness of the human psyche across time and culture.