Charles Sanders Peirce

Charles Sanders Peirce (pronounced like "purse") lived from September 10, 1839, to April 19, 1914. He was an American scientist, mathematician, logician, and philosopher, often called "the father of pragmatism." In 1934, philosopher Paul Weiss described him as "the most original and versatile of America's philosophers and America's greatest logician." Bertrand Russell later said in 1959 that Peirce was "one of the most original minds of the later nineteenth century and certainly the greatest American thinker ever."

Trained as a chemist, Peirce spent thirty years working as a scientist. He made significant contributions to logic, including theories of relations and quantification. C. I. Lewis noted that Peirce's contributions to symbolic logic were more numerous and varied than those of any other writer, at least in the nineteenth century. For Peirce, logic also covered much of what is now called epistemology and the philosophy of science. He viewed logic as the formal branch of semiotics, the study of signs, and is considered a founder of that field. This work foreshadowed the later debate between logical positivists and proponents of philosophy of language that dominated 20th-century Western philosophy. His study of signs also included a tripartite theory of predication.

Peirce defined abductive reasoning and rigorously formulated mathematical induction and deductive reasoning. He was one of the founders of statistics. As early as 1886, he realized that logical operations could be carried out by electrical switching circuits, an idea used decades later to create digital computers.

In metaphysics, Peirce was an "objective idealist" in the tradition of Immanuel Kant and a scholastic realist about universals. He believed that continuity and chance were real features of the universe, calling these views synechism and tychism respectively. He also held that epistemic fallibilism and anti-skepticism went along with these ideas.

Peirce was born at 3 Phillips Place in Cambridge, Massachusetts, to Sarah Hunt Mills and Benjamin Peirce, a Harvard professor of mathematics and astronomy. At age twelve, he read his older brother's copy of Richard Whately's *Elements of Logic*, the leading English-language logic text at the time, sparking a lifelong fascination with logic and reasoning. From his late teens onward, he suffered from a nervous condition then called "facial neuralgia," now diagnosed as trigeminal neuralgia. His biographer, Joseph Brent, wrote that during the pain, Peirce was "at first, almost stupefied, and then aloof, cold, depressed, extremely suspicious, impatient of the slightest crossing, and subject to violent outbursts of temper." This may have led to his social isolation later in life.

He earned a Bachelor of Arts and a Master of Arts (1862) from Harvard. In 1863, the Lawrence Scientific School awarded him a Bachelor of Science degree, Harvard's first summa cum laude in chemistry. His academic record was otherwise undistinguished. At Harvard, he began lifelong friendships with Francis Ellingwood Abbot, Chauncey Wright, and William James. One of his instructors, Charles William Eliot, formed an unfavorable opinion of Peirce. This proved fateful, as Eliot, while President of Harvard from 1869 to 1909, repeatedly vetoed Peirce's employment at the university.

Between 1859 and 1891, Peirce worked intermittently for the United States Coast Survey (renamed the Coast and Geodetic Survey in 1878), where he enjoyed the protection of his influential father until the latter's death in 1880. At the Survey, he worked mainly in geodesy and gravimetry, refining the use of pendulums to measure small local variations in Earth's gravity. This employment exempted him from the American Civil War, which would have been awkward since the Boston Brahmin Peirces sympathized with the Confederacy. No Peirce family members volunteered or enlisted. Peirce grew up in a home where white supremacy was taken for granted and slavery considered natural. His father described himself as a secessionist until the war began, then became a Union partisan and donated to the Sanitary Commission, the leading Northern war charity. Peirce liked to use this syllogism to illustrate the unreliability of traditional logic (since the first premise arguably assumes the conclusion): All Men are equal in their political rights. Negroes are Men. Therefore, negroes are equal in political rights to whites.

He was elected a resident fellow of the American Academy of Arts and Sciences in January 1867. The Survey sent him to Europe five times, first in 1870–1871, as part of a group to observe a solar eclipse on December 22, 1870. There, he sought out British mathematicians and logicians Augustus De Morgan, William Stanley Jevons, and William Kingdon Clifford, whose thinking resembled his own. In 1875, he conducted experiments at the Geneva Observatory with his reversible pendulum and commissioned a vacuum chamber for it in Plainpalais. This work led in 1901 to the Earth ellipsoid proposed by Friedrich Robert Helmert, whose parameter values were remarkably close to reality. From 1869 to 1872, he worked as an assistant at Harvard's astronomical observatory, doing important work on determining the brightness of stars and the shape of the Milky Way.