The solidarity of minds has now become so great, the currents of ideas, like the currents in the atmosphere, move so quickly and create, in circumstances so different and so far apart, states of soul so similar that many who read these studies, and who are struggling with the same difficulties as those which have so long engaged the author's thoughts, may find both interest and profit in seeing how he has succeeded in satisfying himself. Those even who have never reflected on these questions, or have lightly turned from them because they deemed them insoluble, will not perhaps object to be directed to them by one who wishes, not to check their freedom of thought, but to stimulate them to exercise it. Who, at the close of his secret meditations, on the confines of his knowledge, at the end of his affections, of the joys he has tasted, of the trials he has endured, has not seen rising before him the religious question--I mean the mysterious problem of his destiny? Of all questions it is the most vital. Men may be turned from it for a time by manifold distractions and by a sense of powerlessness to solve the question, but it is impossible that they should not return to it. Has life a meaning? Is it worth living? Our efforts, have they an end? Our works and our thoughts, have they any permanent value to the universe? This problem, which one generation may evade, returns with the next. Each new recruit to the human race brings the problem along with him, because he wishes to live, and to live is to act, and all action requires a faith. It is of the young that I have thought while preparing these pages, and it is to them that I dedicate them.