Inference in the Light of Logic

A longstanding tradition understands logic as the study of deductive inference---a distinctive mental activity in which one adopts new conclusions on the basis of accepted premises. Yet this conception is strangely absent from contemporary debates in the philosophy of logic. Inference in the Light of Logic seeks to restore its place by leveraging and extending recent research on inference and bringing it into contact with logical issues.

James R. Shaw contends that a renewed focus on inference allows logic to recover explanatory resources that clarify its normative role in reasoning. If logic is understood as studying inference, we uncover a simple, exceptionless principle explaining why logical consequence is normative for reasoning---a principle whose elusiveness has proved puzzling to many theorists. Conversely, logical inquiry can clarify the nature of inference. Probing why logical impossibility constrains thought---that is, why we generally cannot imagine what is logically impossible---uncovers a cognitive relation that helps to constitute deductive inference, and explains some of its most puzzling features. This in turn reveals integral connections between deductive inference and metaphysical necessity.

Construing logic as the study of inference thus promises to recover the distinctive normative, epistemic, and metaphysical significance traditionally associated with logic-significance that rival conceptions often struggle to capture. In this way, Inference in the Light of Logic offers a starting point for rethinking the foundations of logic and provides a basis for giving the inferential conception of logic a more prominent role in contemporary debates.

James R. Shaw is Associate Professor of Philosophy at the University of Pittsburgh. He is the author of Wittgenstein on Rules: Justification, Grammar, and Agreement.