Thus, here also, at the very source of all our certainty, of the worth attributable to the least or greatest of our thoughts and feelings and acts, we already find the three elements: indubitable sensation, clear thought, warm faith in and through action. And thus life here already consists of multiplicity in unity; and what in it is absolutely indubitable, is of value only because it constitutes the indispensable starting-point and stimulation for the apprehension and affirmation of realities not directly experienced, not absolutely undeniable, but which alone bear with them all the meaning, all the richness, all the reality and worth of life. 2. _The three links in the chain of Reflex Action._ We can also find this same triad, perhaps more simply, if we look to Psychology, and that most assured and most far-reaching of all its results, the fact and analysis of Reflex Action. For we find here that all the activities of specifically human life begin with a sense-impression, as the first, the one simply _given_ element; that they move into and through a central process of mental abstraction and reflection, as the second element, contributed by the mind itself; and that they end, as the third element, in the discharge of will and of action, in an act of free affirmation, expansion, and love. In this endless chain composed of these groups of three links each, the first link and the last link are obscure and mysterious: the first, as coming from without us, and as still below our own thought; the third, as going out from us, and seen by us only in its external results, never in its actual operation, nor in its effect upon our own central selves. Only the middle link is clear to us. And yet the most mysterious part of the whole process, the effect of it all upon the central self, is also the most certain and the most important result of the whole movement, a movement which ever culminates in a modification of the personality and which prepares this personality for the next round of sense-perception, intellectual abstraction, ethical affirmation and volitional self-determination,--acts in which light and love, fixed and free, hard and cold and warm, are so mysteriously, so universally, and yet so variously linked. IV. DISTRIBUTION OF THE THREE ELEMENTS AMONGST MANKIND AND THROUGHOUT HUMAN HISTORY. Let us now watch and see where and how the three elements of Religion appear among the periods of man’s life, the human professions, and the races of mankind; then how they succeed each other in history generally; and finally how they exist among the chief types and phases of the Oriental, Classical Graeco-Roman, and Judaeo-Christian religions. 1. _The Elements: their distribution among man’s various ages, sexes, professions, and races._