1916 – 2013
Peter Thomas Geach (1916–2013) was a British analytic philosopher whose work in logic, philosophy of language, and medieval philosophy proved foundational for several contemporary debates. He is best known for his analyses of reference, predication, and anaphora, as well as his contributions to Catholic philosophy of religion. His treatment of pronouns of laziness and cross-sentential anaphora in 'Reference and Generality' (1962) directly anticipated the problems that Discourse Representation Theory was later developed to solve.
Formulated 'donkey sentence' examples of anaphoric pronouns that resisted classical quantifier analysis, inspiring DRT and dynamic semantics
Identified the Frege-Geach problem, showing that non-cognitivist moral theories cannot account for the logical behavior of moral terms in embedded contexts
Developed a neo-Fregean theory of reference and predication in 'Reference and Generality' (1962), challenging Russell's theory of descriptions
Authored 'Mental Acts' (1957), a rigorous analytic treatment of intentionality and concept acquisition
Contributed to revival of Thomistic logic and philosophy of religion within analytic philosophy