the light by which it sees is not a fantastic brightness. No, replies Descartes; reason sees a true light; and this is how he proves it: I am, I know myself; that is certain. I know myself as a limited and imperfect being; that again is certain. I conceive then infinity and perfection; that is not less certain; for I should not have the idea of a limit if I did not conceive of infinity, and the word _imperfect_ would have no meaning for me, if I could not imagine perfection, of which imperfection is but the negation. Starting from this point, the philosopher proves by a series of reasonings that the conception of perfection by our minds demonstrates the real existence of that perfection: God is. He adds, that the existence of God is more certain than the most certain of all the theorems of geometry. You will observe, Gentlemen, that the man who speaks in this way is one of the greatest geometricians that ever lived. He has found God, he has found the light. Reason does not deceive, when it is faithful to its own laws: the senses do not deceive, when they are exercised according to the rules of the understanding. Error is a malady; it is not the radical condition of our nature; it is not without limits and without remedy, for the final cause of our being is God, that is to say truth and goodness. From everlasting God was true, For ever good and just will be, says one of our old psalms. Faith in the veracity of God--such is the ground of the assurance of believers; such is also the foundation on which has been raised the greatest of modern philosophies. Without the knowledge of God and faith in his goodness, man remains plunged in irremediable doubt, possessing only this single, poor, and frightful certainty: I am; and I exist perhaps only to be eternally deceived. But, it has been said, and it needed no great cleverness to say it--What a strange way is this of reasoning! Here is a man who first proves that God is, by means of his reason; and then proves that his reason is good because God is. His reason demonstrates God to him, and God demonstrates his reason to him: it is an argument of which any schoolboy can at once see the fallacy; it is manifestly a vicious circle. This has been said again and again by persons who have neglected a sufficiently simple consideration. The error is apparently a gross one; is it not likely that the argument has been misunderstood? Ought we not to look very closely at it, before declaring that one of the most lucid minds that have ever appeared in the world left at the basis of his doctrine a fault of logic which any schoolboy can discover? Self-sufficient levity of spirit is not the best means of penetrating the thought of leading minds; and it very often happens to us to fail of understanding because we have failed in respect.