UC San Diego

This dissertation is an exploration of the expressive conception of logic, as found in the work of Robert Brandom. I situate the expressive conception against a historical background of thought about logic, investigate the key notion of material inference on which the expressive conception rests, and argue that the expressive conception counts as a form of psychologism about logic which avoids many of the difficulties faced by older forms of psychologism. Finally, I argue that the expressive conception can make sense of logic's normative import, and offer as a test case the normative significance of validity