Fortunately we are informed that the nebular hypothesis of Kant "is far from showing a fully distinct condition of the world-medium or of explaining how matter arrived at a similar state." This is really very fortunate for Kant who is to be congratulated on having been able to trace the existing celestial bodies to the nebular condition, and who yet does not allow himself to dream of the self-contained unchanged condition of matter. It is to be remarked by the way that although the nebular condition of Kant is supposed to be the original vapor-form of matter, this is to be understood merely relatively. It is to be understood on the one hand as the original vapor form of the heavenly bodies, as they are at present, and on the other hand as the earliest form of matter to which we have been able to trace our way backwards. The fact that matter passed through an endless series of other forms before arriving at the nebular state is not excluded from this conception but is on the other hand rather included in it. Herr Duehring is at an advantage here. Whereas science comes to a halt at the existence of the nebulous state his quack science carries him back to that "Condition of the development of the world which cannot be called actually static in the present sense of the word but most emphatically cannot be called dynamic. The unity of matter and mechanical force which we call the world is, so to speak, a formula of pure logic, to signify the self-contained condition of matter as the point of departure of all enumerable stages of material progress." We have obviously not yet got away from the original self-contained condition of matter. Here it is explained as consisting of mechanical force and matter, and this as a formula of pure logic, etc. As soon then as the unity of matter and mechanical force is at an end evolution proceeds. The formula of pure logic is nothing but a lame attempt to make the Hegelian categories "an Sich and fuer Sich" of use in a philosophy of realism. In "an Sich" according to Hegel the original unity of a thing consists; in "fuer Sich" begins the differentiation and movement of the concealed elements, the active antithesis. We shall therefore depict the original condition as one in which there is a unity of matter and mechanical force and the transition to movement as the separation and antithesis of these two elements. But we have not thereby established the proof of the real existence of the fantastic original condition but only this much that it exists according to the Hegelian category "an Sich" and just as fantastically disappears according to the Hegelian category "fuer Sich."