Scientific naturalism, or scientism, is the theory that science has all the answers. This book argues that not all philosophical explanations can be reduced to scientific ones. Refuting support for scientism, it suggests that reliabilist and causal theories of epistemic justification are unsound.

In seeking to defend a form of naturalism that avoids both scientism and the reduction of philosophy to science, Robert Almeder defines philosophy and distinguishes it from the domain of natural science by showing how a good philosophical explanation, while empirically testable, differs from a good scientific explanation.