This book is an attempt to present the traditional Scholastic philosophy of man's nature in a fresh light, from a point of view that may make is more acceptable to the modern scientific mind. This should please the philosopher looking for a new presentation, and the psychologist looking for philosophical orientation. The object is not to dispense with either psychology or philosophy: marriage is never the reduction of one to the other-vive la difference! That the two are compatible is the theme of this book. It is up to the reader to decide whether the result is a happy mating or a mismatch.