This chapter is divided into four parts. After an introduction, which shows Peirce's place in the history of semiotics, part 1 exhibits the different stations which Peirce passed in his foundation of semiotics. It starts with Peirce's Harvard Lectures, held in 1865, on "The Logic of Science" and ends with the correspondence between Peirce and Lady Welby which ran from 1903 to 1911. Part 2 analyses the foundations of Peirce's semiotics from a systematic point of view. Part 3 is concerned with the fundamental and universal role, which Peirce ascribes to "the most general science," that is, semiotics, and its significance for a new theory of knowledge constructed in semiotic terms. Part 4 discusses some aspects of Peirce's consensus theory in relation to possible pragmatic universals and goes some way towards answering the question of whether, and in what way, situative speech (in contrast to abstract "language") can be made the object of logical analysis.