Clippings

In 1830, Augustus De Morgan wrote that “no word or sign of arithmetic or algebra has one atom of meaning,” so that their interpretations should be open and arbitrary, not restricted to ordinary numbers and magnitudes. By 1840, Duncan Gregory had added that these symbols could represent operations, not just numbers. Building on this, in 1847 George Boole used algebraic symbols to represent members of a “set”… Not only did Boole show the close relation of logic to mathematics, he also emphasized that the form, rather than the content, of the symbols is crucial. For this reason, Bertrand Russell credits Boole with having discovered pure mathematics, “the greatest discovery of the nineteenth century.”