Proposes an original existential-phenomenological theory of knowledge, philosophical systems, and theory of the world. The theory is developed through a critical analysis of the epistemology and metaphysics of C.I. Lewis, and is built around the idea of interpersonal understanding and poetic language. The author also attempts to clarify the logic and theory of transcendental argument, which underlies all personal involvement and reflection and thus all existential-phenomenology. Good supplementary reading for courses in existentialism, phenomenology and metaphysics.