A British mathematician and logician, Augustus De Morgan was born at Madura, India, where his father was an army officer. After early education in the west of England, he entered Trinity College, Cambridge, in 1823 and graduated fourth wrangler in 1827. His refusal to subscribe to the religious tests then in force precluded him from further advancement at Cambridge, but he was fortunate enough to be appointed first professor of mathematics at the newly opened University of London. Because of his habit of resigning on matters of principle, he twice vacated this chair, once at the beginning and once at the end of his career; but he enjoyed, in the interval, the highest repute and affection as a teacher and had many pupils who later achieved distinction.

In addition to numerous important papers on the foundations of algebra and the philosophy of mathematical method...