Now, up to the present time, the positive mode of thought has not shown itself in a position to respond to this demand. It has only produced individual sciences. Positive Science has been “special” and fragmentary, always attached to the investigation of a more or less restricted group of phenomena. With a laudable prudence, which has made her strength, she has applied herself solely to works of analysis and partial synthesis. She has never ventured upon a synthesis of the whole of the real within our reach. Until now theologies and metaphysics alone have made the effort, and this office is, still to-day, the chief reason of their existence, this office must be fulfilled. The human mind is carried, by a spontaneous and necessary movement, towards the point of view of the universal. Sooner than leave the philosophical problems without an answer, it would remain attached indefinitely to the solutions, chimerical as they are, which the theologies and metaphysics offer him. In short, in the present state of things, the positive mind is “real” but “special.” The theologico-metaphysical mind is “universal” but “fictitious.” We can neither sacrifice the “reality” of science, nor the “universality” of philosophy. Which is the way out of this difficulty? Three solutions alone are conceivable: 1. To find a reconciliation which will make it possible for the two modes of thought to coexist without contradiction: 2. To re-establish unity by making the theologico-metaphysical method universal: 3. To re-establish unity by making the positive method universal: II. The first solution at first sight appears to be the most acceptable. Why should not the positive investigation of the divers orders of natural phenomena be reconciled with a theological or metaphysical conception of the universe? Nothing prevents one from conceiving the phenomena as governed by invariable laws, and from seeking at the same time, by another method, for the reason which renders nature in general intelligible. Positive science liberated at last from theology and metaphysics, would assure them of the independence which she claims for herself. Thus, with growing precision would be fixed the boundaries on the one hand of the domain proper of positive science, and on the other that of the speculation which goes beyond experience.