Charles Sanders Peirce -- the family name was earlier spelled "Pers" and thus is pronounced like "purse" -- was an American philosopher, scientist, and humanist. An intellectual figure of extraordinary power and accomplishment, Peirce was -- among many other things -- the primary founder of the distinctively American philosophical tradition called "pragmatism" and a mentor of the other founding figures, such as William James, John Dewey, and Josiah Royce. Some other of many figures associated in one way and another with this tradition are G. H. Mead, C.I. Lewis, Justus Buchler, Richard Rorty, and Hilary Putnam.
      Peirce is also the primary source of the contemporary philosophical conception of "semiotic" as a general theory of representation and interpretation. As developed by Peirce, semiotic is a phenomenologically based and highly generalized critical theory -- a logic with application beyond the traditional domain to which logic in the ordinary sense is restricted -- and can also be understood to be a general theory of interpretation which provides analytical instruments applicable to representation and significance of every sort with no privileging of distinctively linguistic conceptions. Peirce's semiotic is primarily oriented toward communication rather than language, and is distinct from the semiotics (originally called "semiologie" or "semiology") developed by extrapolation from the linguistics of Ferdinand de Saussure. Umberto Eco is a well-known semiotic theorist and analyst as well as novelist whose work reflects both traditions, and Roman Jakobson is one of a number of influential linguists who have attempted to broaden the conception of linguistics as a science by incorporating aspects of Peirce's communicational conceptions. Peirce's semiotic is much broader in conception and possible application than these comparisons might tend to suggest, though.

Peirce's higher degree was in chemistry, and he made his living as a physical scientist (astronomy, geodesy, metrology), and contributed extensively to an astonishing number of scientific fields. (For example, Peirce was the originator of the practice of using the wave length of sodium light as a replacement for reference to the Paris Meter, was the first to do substantial work in experimental psychology in this country, and was among the earliest to open up the field of topology for exploration.) Yet he always regarded logic in its most general sense as his real vocation, his expertise in the sciences providing the substantive basis for his claim to understanding what inference is, and he is by far the most accomplished logician of modern times. Thus the formal deductive logic now in use was independently developed by Peirce and by the German logician Gottlob Frege, but it was Peirce's notation, as modified by Giuseppe Peano, that provided the basis for it in its present form. Peirce was also concerned to develop a far more comprehensive conception of logic than Frege, including non-deductive as well as formal logic, and he experimented with various special types of formal logic, such as modal, many-valued, and "fuzzy" logics.
      Peirce believed that his most valuable contribution to logic on the formal side was a method of graphical representation for logical relationships which he called "existential graphs". The significance of this was not readily apparent until the development of computer-based representation of graphical inference, but a version of his system called "conceptual graphs" is now being developed extensively by scores of computer scientists around the world as a knowledge representation schema for artificial intelligence application, following the work of John Sowa, an IBM researcher.
      In philosophy of science, Peirce made many contributions as well, and was an early proponent of the relative frequency conception of probability. The best known of his ideas at present is perhaps his conception of scientific inquiry as involving "abduction" -- inference to an explanatory hypothesis as a part of a holistic cycle of inference which includes the previously recognized inductive and deductive forms of inference. (Peirce's pragmatism -- the term "pragmatism" itself originated with him -- is closely connected with this.) Karl Popper's idea of science as proceeding by "conjecture and refutation" is akin to Peirce's, as Popper recognized, though apparently arrived at independently somewhat later. In Peirce's version of this the significance of this conception is not limited to philosophy of science: the recognition of abductive thinking -- which is essentially creative and "intuitive" in character -- as fundamental in scientific inquiry opens up the possibility of a systematic integration of imagination and the arts and humanities with the sciences at a fundamental level. Since Peirce has as many devotees in the arts and humanities as in the sciences at present, this seems a promising connection.

These are only hints at the ideas -- a few of many -- that have emerged from Peirce's work, and he is often cited by professionals as the most profound and original of American philosophers. Indeed, there is some basis for arguing that nearly everything distinctive about American philosophy can be found in his work in one form or another, as will be increasingly apparent to the visitor to this website as materials are contributed to it that demonstrate how extensive his contribution actually was. Until recently, he has usually been thought of as "a philosopher's philosopher" whose work is too recondite and difficult to be of interest to any but professionals in philosophy; but within the past decade or two it has become increasingly apparent that the difficulty in understanding him has been due to the fact that he jumped beyond the concerns that have occupied the generality of academic philosophers in the 20th century to open up inquiry into topics that are only just now moving to the forefront of general interest. In fact, he is frequently understood better at present by people outside of the ranks of academic philosophy than by those within.
      Peirce wrote voluminously and on a wide variety of topics, and published extensively both in the sciences and in philosophy, but certain peculiarities of his life and times and of the institutionalization of science and philosophy in the U.S. in the late 19th Century put him at odds with the "powers that be" in academia. This resulted in an inadequate representation of his published work in collections of it after his death, and has kept his unpublished work, most of which is now contained in a huge manuscript collection of more than 100,000 pages, from being known in detail except to a relatively small number of scholars because of the difficulties of accessing it effectively.
      One of the major aims in implementing this website is to rectify this -- a rectification long overdue -- by providing an on-line environment that enables a cooperation of the specialized editorial and scholarly community with the general world-wide user community, many of whom have no connection with academia at all, in making this intellectual treasure-trove universally and unrestrictedly available. The creation of the world wide web has made this possible for the first time by providing a common and universally accessible space for those technologically enabled to access it. To fill that space with value is the common obligation of all developers of it.

If you are interested in learning more about Peirce you will want to read "The Wasp Leaves the Bottle," an excellent overview by Josiah (Lee) Auspitz, originally published in The American Scholar, which has been made available here at the virtual Arisbe by the author. Auspitz uses the occasion of a review of recent work on Peirce to develop the best thumbnail sketch of the man, his work, and the reasons for the increasing interest in him that you will find.