Does science have all the answers? The view that it does is known as scientific naturalism or scientism, and is now commonly advanced under the label 'naturalized epistemology'. Scientism holds that the only legitimate claims about the world are those that can be tested by the methods of the natural sciences. Robert Almeder argues that scientism is rationally indefensible, but that there is a rationally defensible form of naturalism - 'harmless naturalism' - which does not reduce philosophical explanations to scientific ones. This book begins by refuting the arguments for the most radical form of scientism, the Replacement Thesis, which derives from Quine. Almeder goes on to refute the Transformational Thesis, an allegedly distinct form of naturalized epistemology offered by Alvin Goldman and others. Finally, there is an examination of 'harmless naturalism', a position which holds that there are some questions about the world whose answers are not to be sought in natural science.