“I see that all these complications of society are artificial,” adds Rousseau; “man has made them; they are not good, and let us tear them down and make anew.” These utterances echo all over France and Europe. “The state is merely a machine by which the few exploiter the many”—“off with crowns!” Thereupon they snatch off the crown of poor Louis, and his head follows with it. “Reason” is enthroned and dethroned. Thirty years of war satiates at length this negative second period, and the third phase begins. Its characteristic is to be constructive, not to accept the heritage of the past with passivity, nor wantonly to destroy, but to realize itself in the world of objectivity—the world of laws and institutions. The first appearance of the second phase of consciousness is characterized by the grossest inconsistencies. It says in general, (see D’Holbach’s “Système de la Nature”): “The immediate, only, is true; what we know by our senses, alone has reality; all is matter and force.” But in this utterance it is unconscious that matter and force are purely general concepts, and not objects of immediate consciousness. What we see and feel is not matter or force in general, but only some special form. The self-refutation of this phase may be exhibited as follows: I. “What is known is known through the senses: it is matter and force.” II. But by the senses, the particular only is perceived, and this can never be _matter_, but merely a _form_. The general is a mediated result, and not an object of the senses. III. Hence, in positing matter and force as the content of sensuous knowing, they unwittingly assert mediation to be the content of immediateness. The decline of this period of science results from the perception of the contradiction involved. Kant was the first to show this; his labors in this field may be summed up thus: The universal and necessary is not an empirical result. (General laws cannot be sensuously perceived.) The constitution of the mind itself, furnishes the ground for it:—first, we have an _a priori_ basis (time and space) necessarily presupposed as the condition of all sensuous perception; and then we have categories presupposed as the basis of every generalization whatever. Utter any general proposition: for example the one above quoted—“all is matter and force”—and you merely posit two categories—Inherence and Causality—as objectively valid. In all universal and necessary propositions we announce only the subjective conditions of experience, and not anything in and for itself true (i. e. applicable to things in themselves). At once the popular side of this doctrine began to take effect. “We know only phenomena; the true object in itself we do not know.”