The paper argues that contemporary consciousness studies can profit from Charles S. Peirce’s philosophy of consciousness. It confronts mainstream tendencies in contemporary consciousness studies, including those which consider consciousness as an unsolvable mystery, with Peirce’s phenomenological approach to consciousness. Peirce’s answers to the following contemporary issues are presented: phenomenological consciousness and the qualia, consciousness as self-controlled agency of humans, self-control and self-reflection, consciousness and language, self-consciousness and introspection, consciousness and the other, consciousness of nonhuman animals, and the question of a (...) quasi-consciousness of the physical universe. A detailed account of Peirce’s three modes of consciousness is presented: primisense, qualisense or feeling-consciousness, altersense, and medisense, the consciousness of cognition, thought, and reasoning. In contrast to consciousness studies that establish a rather sharp dividing line between conscious and unconscious states of mind, Peirce adopts the principle of synechism, the theory of continuity. For him, consciousness is a matter of degree. An important difference between Peirce’s concept of qualia and current theories of qualia in human consciousness is discussed. The paper shows how consciousness, according to Peirce, emerges from unconscious qualia and vanishes into equally unconscious habits. It concludes with a study of the roles of qualia, habit, and self-control in Peirce’s theory of signs, in particular in qualisigns and symbols, and the question of signs as quasi-conscious agents in semiosis. (shrink)