Alfred Tarski is, with Kurt Godel, one of the founders of contemporary logic. His papers on the theory of truth and logical consequence, as well as his studies on axiomatic geometry, are commonly identified as the starting point of formal semantics and model theory. Born Alfred Teitelbaum in Russian-occupied Poland, he converted to Catholicism and changed his name to Tarski, apparently in an outburst of Polish nationalism following the Russian retreat in WorldWarI. Whatever the motive, the conversion did little to mollify the numerous anti-semites in Polish academia: Tarski wrote his seminal papers while teaching mathematics in high school. He later moved to the United States and had a distinguished career at the University of California, where his students included Solomon Feferman and Richard Montague.