Before the need for mystical belief can occur to one, one must have been reared in an atmosphere of faith, or else in an atmosphere of doubt; and both these states of mind are equally unknown to the earlier and simpler races of humanity. Or, more accurately, they are perfectly acquainted with faith, but it is the naïve faith of eye and ear; they possess the perfect confidence that every sentient being has in his five senses, and in all that there is nothing religious properly so-called. I remember the astonishment I felt in my infancy when I first saw the words doubt and faith; it was in some verses, and the poet was singing, with much eloquence, all the horrors of doubt. I perfectly understood what it was to doubt a fact, or to believe in it, but I bothered my head in vain to discover what one meant by doubt simply: What was there so terrible about being in doubt on matters with which one was insufficiently acquainted? The word faith was equally unintelligible to me, for I had as yet no conception of believing in anything except what was certain. The case of primitive man is exactly the same. He no more experiences a mystical need to believe than he experiences a mystical need to get drunk before having tasted wine. Religious sentiment does not make its appearance in him suddenly, does not simply step out on the stage. There are no lacunæ in the human soul, it is a prey to invincible continuity. Such a sentiment must come gradually by a slow adaptation of the spirit to the inexact ideas supplied to one by the senses. Man, imagining himself to live in the bosom of a society of gods, inevitably accommodates himself to so novel a habitat. Every society, human or divine, creates the individual member in its own image; draft the labourer for a soldier, let the villager become a citizen, they acquire of necessity new gestures and sentiments which, upon their return to their former habitat, they once more in a measure lose. The case is inevitably the same for mankind and religion. As the most sociable of beings, man is also the most readily subject to the influence of those with whom he lives or believes himself to live. The gods, whom we create more or less in our own image, thereupon, by an inevitable reaction, return the compliment. A religious instinct, such as M. Renan describes, is in a large part the work of this sort of reaction and of education; if it possesses profound roots in our being, the reason is that it was planted in us in our infancy, that it speaks to us with the voice of our childhood, and takes us back to our earliest years; often a word, a thought with which we have been struck at some former time, without, however, having understood it, unexpectedly reawakens in us, reverberates in our memory; it is but an echo, and it appeals to us as if it were a voice. The rôle played by heredity in the formation of one’s character has been noticeably exaggerated; the influence of education is at the