Naturalism and the Question of Realism

According to naturalism, philosophy is part of science. Its aim is thus to acquire synthetic knowledge of the world. Philosophy's methods of discovery - its use of a priori reasoning, conceptual analysis, and thought experiments - are legitimate to the extent that they further this broader scientific aim, naturalists aver. A very different view of philosophy sees it as distinct from science in both aim and methods. Philosophy aims to discover analytic knowledge through a priori reasoning on this competing view. This view of philosophy emphasizes rational intuitions as a source of evidence for the truth of the conclusions attained by a priori reasoning. Naturalism has been criticized as incompatible with realism, the view that the existence and nature of the world are independent of human conceptions of it. What naturalistic sense could be made of the idea that a scientific theory that passed every conceivable observational and theoretical test might yet be false? Isn't such a notion of truth, presupposed by realism, simply at odds with the idea that science is the arbiter of truth? Further, doesn't the attempt to marry naturalism and realism open the door to a radical kind of skepticism, one that makes it impossible to know that all our experiences of the world are not illusory? This chapter explores the nature of philosophy and philosophical theorizing from the perspective of naturalistic realism, arguing that naturalism and realism are compatible in spite of attempts to show they are not. The chapter reviews the leading arguments for incompatibility - Hilary Putnam's model-theoretic argument (MTA) and the brains-in-a-vat argument - and finds that they do not establish this conclusion. Further, it shows that the view that philosophy is distinct in aim and methods from science - a view that places its faith in the evidential warrant supplied by rational intuition - is at odds with what cognitive science has shown about the nature and reliability of these sorts of intuition.