In this little book I have attempted to deal with some of the questions which must be asked if one is to gain some understanding of the nature of human nature. The two most important of these questions are: (1) How much of the biological enters into the making of human nature? and (2) How much of the social experience of the individual enters into the making of that nature? Hence, the title of this book. No one is, of course, in a position to answer these questions completely. What I have tried to do in the present volume is to clarify the issues, to set down the relevant facts as scientists have come to know them, and to examine some of the representative theories concerning the bio-social nature of man.
Goethe once remarked that where an idea is wanting a word can always be found to take its place. In the area of discussion with which this book is concerned - human nature - words, alas, have too often passed for ideas.