The metaphysical part of this book is largely concerned with realism issues. Michael Devitt starts with realism about universals, dismissing Plato's notorious 'one over many' problem. Several chapters argue for a fairly uncompromising realist view of the external physical world of commonsense and science. Both the nonfactualism of moral noncognitivism and positivistic instrumentalism, and deflationism about truth, are found to rest on an antirealism that is hard to characterize. A case is presented for moral realism. Various biological realisms are considered. Finally, an argument is presented for an unfashionable biological essentialism.

The second part of the book is epistemological. Devitt argues against the a priori and for a Quinean naturalism. The intuitions that so dominate 'armchair philosophy' are emipirical not a priori.

Throughout the book there is an emphasis on distinguishing metaphysical issues about what there is and what it's like from semantic issues about meaning, truth, and reference. Another central theme, captured in the title, is that we should 'put metaphysics first'. We should approach epistemology and semantics from a metaphysical perspective rather than vice versa. The epistemological turn in modern philosophy, and the linguistic turn in contemporary modern philosophy, were something of disasters.