Schopenhauer's metaphysics of the unconscious in its relation to consciousness is contrasted with later psychoanalytic concepts of individual and collective unconscious influences on conscious thought, causally affecting behavior and the physical expression of cognitive and emotional states. Schopenhauer seals off consciousness from penetration by unconscious elements, while Freud and Jung consider the possibility of unconscious desires, fears, hopes, and the like surfacing perhaps therapeutically into a subject's awareness. The similarities and differences between Schopenhauer's metaphysics and Freud's and Jung's assumptions about the relation between consciousness and the unconscious are critically considered. Schopenhauer's metaphysics of the unconscious conditions but denies the logical possibility of unconscious elements emerging from behind the curtain into consciousness. Freud and Jung in the psychoanalytic tradition are theoretically committed on the contrary to the causal possibility of an unconscious element emerging with its identity intact into an individual conscious thinker's subjective streaming moments of consciousness.

Dale Jacquette is ordentlicher Professor für Philosophie, Abteilung Logik und theoretische Philosophie, at Universität Bern, Switzerland. He is author of numerous articles on logic, metaphysics, and philosophy of mind, and has recently published "Symbolic Logic, Philosophy of Mind: The Metaphysics of Consciousness, Ontology", "Wittgenstein's Thought in Transition", "David Hume's Critique of Infinity", and "Logic and How it Gets That Way". He has edited the "Cambridge Companion to Brentano", the "Blackwell Companion to Philosophical Logic", and the volume on "Philosophy of Logic" in the Elsevier Handbook of the Philosophy of Science series. His latest book, forthcoming from Springer Verlag, is "Alexius Meinong: The Shepherd of Non-Being".