Charles S. Peirce (1839\u20131914) is widely recognized as America\u2019s greatest philosopher, the originator of pragmatism, and one of the founders of modern mathematical logic. He was also a pioneer in the field of "semiotics," the general theory of signs, and many have regarded him as the father of the contemporary form of the discipline. This volume is a critical edition of unpublished writings spanning almost twenty years (1894\u20131913) that are essential to understand Peirce\u2019s views about signs, their classification, and the relations between semiotics and logical inquiry. It comprises twenty-two selections, a historico-critical introduction, and an editorial apparatus. The selections are prepared following the methods of scho...