"To the healthy man and woman this book is respectfully dedicated. They have done certain things (consciously or subconsciously) in order to bring themselves from infancy to healthy, normal maturity. And if you (who may not be so healthy and normal) will do just these same things, there is no reason why you, too, should not be just as are they. And this little book is our attempt to tell you just what this healthy man and woman did in order to be just what they are. Read it, and then go and do likewise, so far as you are able.