Michael Devitt presents a series of essays with four recurring themes: (i) a sharp distinction between metaphysical issues and semantic ones, (ii) the priority of metaphysical issues over epistemological and semantic issues, (iii) a naturalistic opposition to the a priori taken largely from Quine, (iv) an uncompromising 'realism about the external world'. Topics include Plato's 'one over many' problem, nonfactualism, truth, moral realism, biological realism, biological essentialism, intuitions and their proper role.