What I state as certain is certain for me. It has approved itself as such in my experience. Let others consult their experience, and see how far it tallies with that which is here set forth. A distinction, however, I wish to call attention to between the theory as expounded in the second part of this volume, and the practical applications to be found in the third and fourth parts. Persons who are not trained in metaphysical thinking or interested in it, may do well to omit the reading of the second part. To those who are competent in philosophical thinking, and who disagree with the positions there taken, I may perhaps be permitted to suggest that one can dissent from a philosophy and yet find help in the applications to which it leads. And, after all, it is the practice that counts. With these preliminaries, I now proceed to delineate briefly the stages of inner development which have led me slowly and with much labor to the system of thought described in the following pages. One of the leading principles to which I early gave assent, and to which I have ever since adhered as a correct fundamental insight, is expressed in the statement that every human being is an end _per se_, worth while on his own account.[2] Every human personality is to be safe against infringement and is, in this sense, sacred. There is a certain precinct which may not be invaded. The experience which served me especially as the matrix of this idea was the adolescent experience of sex-life,—the necessity felt of inhibiting, out of reverence for the personality of women, the powerful instincts then awakened.[3] The fact that I had lived abroad for three years in frequent contact with young men, especially students, who derided my scruples, and in the impure atmosphere of three capital cities of Europe, Berlin, Paris and Vienna, where the “primrose path” is easy, tended to make the retention of my point of view more difficult, and at the same time to give it greater fixity, also to drive me into a kind of inward solitude. I felt myself in opposition to my surroundings, and acquired a confidence, perhaps exaggerated, to persevere along my own lines against prevailing tendencies.