Peirce Chase’ing Pythagoras

Despite the common knowledge that there is something “Pythagorean” about Charles Peirce’s phenomenology and classification of signs there is a manifest lack of inquiries into the matter. Perhaps there is too little to go on, as Pythagoras himself did not leave us any writings to consult. Nevertheless, much of ancient Greek philosophy bears an unmistakable Pythagorean stamp, and Iamblichus’ bio - graphy of Pythagoras provides us with enough to get such inquiries started. This paper examines the development of triads, beginning with the Pythagorean one (body, soul, and intellect) and proceeds to those of Immanuel Kant (Experience, Understanding, and Reason) and Peirce’s compatriot and family acquaintance Pliny Earle Chase (Motivity, Spontaneity, and Rationality). The article concludes with an examination of the various triads in Peirce’s early writings, especially around the time of his discovery of Chase’s “Intellectual symbolism”.