1839 – 1914
Charles Sanders Peirce (1839–1914) was an American philosopher, logician, and scientist widely regarded as the founder of pragmatism and one of the most original thinkers in the history of American philosophy. He made foundational contributions to formal logic, semiotics, and the philosophy of science, though much of his work remained unpublished during his lifetime.
Founded pragmatism as a philosophical method for clarifying meaning through practical consequences
Developed semiotics as a systematic theory of signs and their interpretation
Advanced formal logic, including the logic of relations and quantification theory
Introduced abductive reasoning (inference to the best explanation) as a distinct mode of inference
Articulated fallibilism: the view that no belief is immune to revision in light of inquiry