Rosanna Keefe

Rosanna Keefe is currently a Professor of Philosophy at the School of History, Philosophy and Digital Humanities, University of Sheffield. She joined Sheffield in October 1999 after three years as a Research Fellow at Jesus College, Cambridge. Her primary research focuses are in the philosophy of logic and language and metaphysics, particularly the nature of vagueness and its implications for logic and semantics.

• Education
  • BA, University of Cambridge
  • PhD, University of Cambridge

Keefe's research explores the vagueness of natural language, addressing questions about its logic, semantics, and methodology. She is renowned for defending a supervaluationist theory of vagueness, which posits that vague terms lack a definite truth value in borderline cases. Her work also extends to paradoxes like the Sorites Paradox and debates on logical consequence.

The trends in her publications indicate a sustained engagement with vagueness and its semantic modeling, including higher-order vagueness, logical consequence, and the role of context. Her recent articles analyze phenomena such as prefaces, reasoning guides, and essentialism, bridging metaphysics and logical theory.