Object of the lecture: What is the ultimate basis of absolute truth?--Four hypotheses: Absolute truth may reside either in us, in particular beings and the world, in itself, or in God. 1. We perceive absolute truth, we do not constitute it. 2. Particular beings participate in absolute truth, but do not explain it; refutation of Aristotle. 3. Truth does not exist in itself; defence of Plato. 4. Truth resides in God.--Plato; St. Augustine; Descartes; Malebranche; Fenelon; Bossuet; Leibnitz.--Truth the mediator between God and man.--Essential distinctions. We have justified the principles that govern our intelligence; we have become confident that there is truth outside of us, that there are verities worthy of that name, which we can perceive, which we do not make, which are not solely conceptions of our mind, which would still exist although our mind should not perceive them. Now this other problem naturally presents itself: What, then, in themselves, are these universal and necessary truths? where do they reside? whence do they come? We do not raise this problem, and the problems that it embraces; the human mind itself proposes them, and it is fully satisfied only when it has resolved them, and when it has reached the extreme limit of knowledge that it is within its power to attain. It is certain that the principles which, in all the orders of knowledge, discover to us absolute and necessary truths, constitute part of our reason, which surely makes its dwelling in us, and is intimately connected with personality in the depths of intellectual life. It follows that the truth, which reason reveals to us, falls thereby into close relation with the subject that perceives it, and seems only a conception of our mind. Nevertheless, as we have proved, we perceive truth, we are not the authors of it. If the person that I am, if the individual _me_ does not, perhaps, explain the whole of reason, how could it explain truth, and absolute truth? Man, limited and passing away, perceives necessary, eternal, infinite truth; that is for him a privilege sufficiently high; but he is neither the principle that sustains truth, nor the principle that gives it being. Man may say, My reason; but give him credit for never having dared to say, My truth.