Charles Sanders Peirce ( /ˈpɜrs/ like "purse"; September 10, 1839 – April 19, 1914) was an American philosopher, logician, mathematician, and scientist, born at 3 Phillips Place in Cambridge, Massachusetts. Peirce was educated as a chemist and employed as a scientist for 30 years. Today he is appreciated largely for his contributions to logic, mathematics, philosophy, and semiotics, and for his founding of pragmatism. In 1934, the philosopher Paul Weiss called Peirce "the most original and versatile of American philosophers and America's greatest logician".
An innovator in mathematics, statistics, philosophy, research methodology, and various sciences, Peirce considered himself a logician first and foremost. He made major contributions to logic, but logic for him encompassed much of that which is now called epistemology and philosophy of science. He saw logic as the formal branch of semiotics, of which he is a founder. As early as 1886 he saw that logical operations could be carried out by electrical switching circuits, the same idea as was used decades later to produce digital computers.
Charles Sanders Peirce was the son of Sarah Hunt Mills and Benjamin Peirce, himself a professor of astronomy and mathematics at Harvard University, perhaps the first serious research mathematician in America. At 12 years of age, Charles read an older brother's copy of Richard Whately's Elements of Logic, then the leading English-language text on the subject. Thus began his lifelong fascination with logic and reasoning. He went on to obtain the BA and MA from Harvard; in 1863 the Lawrence Scientific School awarded him a B.Sc. that was Harvard's first summa cum laude chemistry degree; and otherwise his academic record was undistinguished (B:54–6). At Harvard, he began lifelong friendships with Francis Ellingwood Abbot, Chauncey Wright, and William James (B:363–4). One of his Harvard instructors, Charles William Eliot, formed an unfavorable opinion of Peirce. This opinion proved fateful, because Eliot, while President of Harvard 1869–1909—a period encompassing nearly all of Peirce's working life—repeatedly vetoed Harvard's employing Peirce in any capacity (B:19-20, 53, 75, 245).