Man thinks, he feels, and he wills: these are the three great functions of the spiritual life. Let us inquire what, without God, would become, first, of thought, which is the instrument of all knowledge; next; of the conscience, which is the law of the will; then of the heart, which is the organ of the feelings. We will begin with thought. Let us go back to the origin of modern philosophy. The labors of Descartes will make us acquainted, under the form clearest for us, with a current of lofty thoughts which does honor to ancient civilization, and which has come down to us through the writings of Plato and St. Augustine. We have seen that Descartes deceived himself, when he thought to separate himself altogether from tradition, and forgot the while how intimately men's minds are bound together in a common possession of truth. He was mistaken, because he confounded the idea, natural to the human mind, of an infinite reason, with the full idea of the Creator; so attributing to the efforts of his own philosophy that gift of truth which he had received from the Christian tradition. But, having so far recognized his error, listen now to this great man, and judge if he were again mistaken in those thoughts of his which I am about to reproduce to you. Descartes strives hard to doubt of all things, persuaded that truth will resist his efforts, and come forth triumphant from the trial. He doubts of what he has heard in the schools: his masters may have led him into error. He doubts of the evidence of his senses: his senses deceive him in the visions of the night; what if he were always dreaming, and if his waking hours were but another sleep with other dreams! He will doubt even of the certainty of reason: what if the reason were a warped and broken instrument? Reason is only worth what its cause may be worth. If man is the child of chance, his thoughts may be vain. If man is the creature of a wicked and cunning being, the light of reason may be only an _ignis fatuus_ kindled by a malicious and mocking spirit. Here is a soul plunged in the lowest abysses of doubt; but it is a manly soul which seeks in doubt a trial for truth, and not a comfortable pillow on which slothfully to repose. How does Descartes upraise himself? By a thought known to every one, and which was already found in St. Augustine: "_Cogito, ergo sum_. I think, therefore I am." Deceive me who will; if I am deceived, I exist. Here is a certainty protected from all assault: I am. But what a poor certainty is this! What does it avail me to have rescued my existence from the abysses of universal doubt, if above the deep waters which have swallowed up all belief floats only this naked and mortifying truth: I am; but I exist only perhaps to be the sport of errors without end. The first step therefore taken by the philosopher would be a fruitless one if it were not followed by a second. An eye is open, and says: I see; but it must have a warrant that