When the traveller, bent on some important quest, makes a prolonged and perilous journey and returns in safety to his friends and neighbors, instinctively those who have known him in former years realize that he is, and he is not, the same person who had dwelt among them. He has seen unfamiliar peoples, traversed strange lands, encountered unexpected dangers. Old prepossessions have been effaced, erroneous opinions have been corrected, new habits of thought have taken the place of old ones and the narrow world of youth has expanded on every side. Naturally, what has happened to him becomes a matter of curiosity and enquiry, and the hero of a great achievement is expected to relate the story of his adventures. The man who, in these revolutionary days, takes religion seriously--there are many who do not--must make a journey which is fraught with as many surprises and filled with as many anxieties--especially if it be a pilgrimage from orthodoxy to personal independence--as that which the explorer encounters in a voyage to the North Pole or the jungles of Africa. At every turning of the way he must be prepared for disillusions and the discovery of facts and errors which call for unlimited courage and boundless faith. Religion is not simply a matter of the emotions, its very perpetuity depends upon that sane and persistent activity of the intellect without which the emotions are tyrannous and fateful. Emotion in religion is the driving force by which religion may be applied to human welfare, but if emotion be not governed and directed by the well-trained intellect, informed by patient thought and the use of all the evidence available from those who are entitled to be summoned as witnesses, the result inevitably is merely a matter of superstition, or a spineless acquiescence in old and futile beliefs. To continue all the while to believe in _religion_ while one is pursuing a course of reasoning which is bound to shatter many of the interpretations of it which one has previously accepted, requires the kind of intellectual endurance and the quality of faith which characterize the inventor, or the scientific explorer.