Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. Whoever wishes to understand the developmental tendencies of love as they manifest themselves at the present day in the course of human history, whoever desires to grasp how remarkably love has been developed, enriched, and ennobled in the course of civilization, must at the outset gain a clear understanding of this apparently dualistic, but in reality thoroughly monistic, nature of the passion.