Charles Peirce
American philosopher, logician and scientist (1839–1914), born in Cambridge, Massachusetts, son of the prestigious Harvard mathematician Benjamin Peirce, who provided him with an exceptionally demanding intellectual education from childhood, and who worked for three decades as a scientist at the United States Coast and Geodetic Survey while developing in parallel, often fragmentarily and without a stable university chair owing to a difficult personality and personal scandals, one of the most original and systematically undervalued philosophical bodies of work in American philosophy during his lifetime. Regarded as the founder of pragmatism, a philosophical current he himself named but which he saw popularised and simplified by William James in a manner Peirce considered a distortion of his original thought, to the point that he rechristened his own version 'pragmaticism', a name 'ugly enough to be safe from kidnappers'. His pragmatic maxim, first formulated in 'How to Make Our Ideas Clear' (1878), establishes that the full meaning of a concept consists in the totality of its conceivable practical effects, a methodological criterion for clarifying ambiguous philosophical concepts that Peirce conceived as a rigorous epistemological tool, not as a theory of truth reduced to utility, as James popularised it. Peirce made fundamental contributions to formal logic, independently developing much of the logic of relations and predicates that would later be consolidated as modern logic, and formulated an original and influential classification of the three basic forms of inference: deduction, induction and abduction, the latter understood as the creative process of generating new explanatory hypotheses, essential to scientific progress and often ignored by traditional logic focused exclusively on deduction and induction. His late metaphysics, developed within his own categorial system of firstness, secondness and thirdness, and his semiotic theory of the sign as a triadic relation among representamen, object and interpretant, exerted a decisive influence on fields as diverse as linguistics, artificial intelligence and communication theory, and have caused Peirce's philosophical reputation, largely ignored during his lifetime, to grow spectacularly since the mid-twentieth century, placing him today among the most original and influential American thinkers of all time.