Frege, (Friedrich Ludwig) Gottlob (1848–1925)

German philosopher, the founder of modern mathematical logic. He created symbols for concepts like ‘or’ and ‘if ... then’, which are now in standard use in mathematics. His Die Grundlagen der Arithmetik/The Foundations of Arithmetic (1884) influenced Bertrand Russell and Ludwig Wittgenstein. Frege's chief work is Begriffsschrift/Conceptual Notation (1879).

Frege was born in Wismar on the Baltic coast and studied at Jena and Göttingen; he became professor at Jena 1879.

Frege incorporated improvements to the Begriffsschrift into his two-volume Grundgesetze der Arithmetik/Basic Laws of Arithmetic 1893–1903, but was devastated to receive a letter from Bertrand Russell 1902 in which Russell asked Frege how his logical system coped with a particular logical paradox in set theory. Frege's system was not able to resolve it, and he was forced to acknowledge his system to be useless.

Although at the time Frege was largely discredited, his innovations have been useful in the development of symbolic logic, and even the problem posed by Russell was resolved by later logico-mathematicians.