The book deals with all the main questions arising within the field in so far as they can be stated and discussed profitably and simply. The topics discussed include the place of reason in knowledge and life, the possibility of knowledge beyond sense-experience, the theory of perception, the relation of body and mind, alleged philosophical implications of recent scientific doctrines, the problem of evil and the existence of God.
From the new introduction by Ralph McInerny:
You are about to read a magnificent introduction not only to a kind of philosophy but to philosophizing itself. Jacques Maritain was a relatively young man when he wrote this book, but his effort is one that attracts any philosopher more and more as he grows older. However odd and unusual what he says becomes, the philosopher yearns to show how even the most abstruse claims can be put into relation with what the reader already knows. That, in its essence, is what teaching is. In this book, the reader will find a wise and certain guide into philosophizing as such. And, in the end, he will find that what he reads is really only a refinement and development of what he and everybody else already knew.