De Morgan, Augustus (1806–71)

Augustus De Morgan was an important British mathematician and logician. Much of his logical work was directed to expanding the traditional syllogistic theory, and to meeting the objections of Sir William Hamilton and his allies to the techniques he used. More important for the future of logic, though, was De Morgan’s work in two areas: the logic of complex (compound) terms, in which he essentially developed the theory of Boolean algebra, and his introduction of the logic of relations as a serious topic for formal logic. His work on probability logic, while flawed, was also significant.