The English mathematician George Boole (1815-1864) invented mathematical, or symbolic, logic and uncovered the algebraic structure of deductive logic, thereby reducing it to a branch of mathematics.

George Boole was born on Nov. 2, 1815, in Lincoln. He attended a primary school of the National Society and then a school for commercial subjects. This was the last of his formal schooling but not the end of his education, for he inherited a talent for self-study from his father, a shoemaker by trade but a philosopher by inclination. At the age of 16 young Boole became an assistant teacher in an elementary school. Four years later he opened his own school.

Meanwhile he had discovered mathematics. Disgusted with the poor quality of the texts that his students had to use, Boole began to study the works of the great mathematicians. Without guidance he mastered these books and was producing original mathematics by 1840, barely 5 years after beginning serious study of the subject.

In 1844 Boole's pioneering paper on the calculus of operators won the Royal Society's gold medal and established his reputation among mathematicians. Three years later he published *The Mathematical Analysis of Logic,* the slim booklet that initiated modern symbolic logic. In it Boole showed how all the ponderous verbalism of Aristotelian logic could be rendered in a crisp algebra that was remarkably similar to the ordinary algebra of numbers. "We ought no longer to associate Logic and Metaphysics, but Logic and Mathematics."

In 1849 Boole finally lost his amateur status. He was appointed professor of mathematics at the new Queen's College in Cork, Ireland. His best-known work, *An Investigation of the Laws of Thought on Which Are Founded the Mathematical Theories of Logic and Probabilities* (1854), is
an elaboration of the 1847 booklet. In 1860 he published a text on the calculus of finite differences which remains the classic on that subject.

Boole married Mary Everest in 1855; she bore him five daughters. Their life together was serene but short, for Boole died on Dec. 8, 1864, of pneumonia. The citizens of Lincoln installed a stained-glass window in the Cathedral to his memory.

Boole's reputation continues to grow. In 1847 he pointed out that the value of his theories would depend largely upon the extent of their applications. Today, along with symbolic logic, Boolean algebra is of central importance in such diverse fields as probability, combinatorial theory, information theory, graph theory, switching theory, and computer design.

## Further Reading on George Boole

The biographical essay on Boole in E. T. Bell, *Men of Mathematics* (1937), contains minor inaccuracies and a questionable character analysis but is otherwise an excellent review of Boole's place in the history of mathematics. For a good discussion of Boole's fundamental ideas see Herbert Meschkowski, *Ways of Thought of Great Mathematicians* (1964). For modern developments consult J. Eldon Whitesitt, *Boolean Algebra and Its Applications* (1961). A concise history of symbolic logic is in Clarence Irving Lewis and Cooper Harold Langford, *Symbolic Logic* (1932; 2d ed. 1959).

## Additional Biography Sources

MacHale, Desmond, *George Boole: his life and work,* Dublin: Boole Press, 1985.