The book seeks to characterize reflexive conceptual structures more thoroughly and more precisely than has been done before, making explicit the structure of paradox and the clear connections to major logical results. The goal is to trace the structure of reflexivity in sentences, sets, and systems, but also as it appears in propositional attitudes, mental states, perspectives and processes. What an understanding of patterns of reflexivity offers is a deeper and de-mystified understanding of issues of semantics, free will, and the nature of consciousness.