This book applies notions from C.S. Peirce’s philosophy, such as semiosis, mind, diagrammatic reasoning, abduction, and habits, to contemporary problems in distributed cognitive science. These problems include distributed cognitive systems, cognitive niche construction, external representations, cognitive artifacts, agency, and emergence. In this movement, Peirce’s approach provides a philosophical framework that reconceptualizes fundamental notions in distributed cognitive science. Among the founders of pragmatism, Charles S. Peirce remains one of the least influential within the pragmatic turn in cognitive science. Nevertheless, Peirce’s theory of mind is processist and externalist, placing it at the center of cognition and the action of external signs. This book is therefore of interest to philosophers of science as well as cognitive scientists and cognitive linguists.