This work is the intellectual biography of the greatest of American philosophers. Peirce was not only a pioneer in logic and the creator of a philosophical movement pragmatism he also proposed a phenomenological theory, quite different from that of Husserl, but equal in profundity; and long before Saussure, and in a totally different spirit, a semiotic theory whose present interest owes nothing to passing fashion and everything to its fecundity. Throughout his life Peirce wrote continually about sign and phenomenon (or phaneron). Consequently his writings must be studied chronologically if they are not to appear incomprehensible or contradictory. One of the merits of this book is to clarify Peirce’s thought by analysing its development chronologically. We follow the evolution of Peirce’s thought from his critique of Kantian logic and Cartesianism (Chap. I, “Leaving the Cave”: 1851-1870) to his discovery of modern logic and pragmatism (Chap. II, “The Eclipse of the Sun”: 1870-1887) and finally to a semiotic founded on a phenomenology the base of which is the logic of relations and the crowning-point scientific metaphysics (Chap. III, “The Sun Set Free”: 1887-1914). The book includes a detailed chronology, a general bibliography, and an index.