the combined application of which one can go further in philosophy, in the same proportion as in the case of an algebraical problem one can accomplish more if two known quantities are given than if only one is given. In accordance with what has been said, the ineradicable falseness of materialism primarily consists in the fact that it starts from a _petitio principii_, which when more closely considered turns out indeed to be a πρωτον φευδος. It starts from the assumption that matter is something absolutely and unconditionally given, something existing independently of the knowledge of the subject, thus really a thing in itself. It attributes to matter (and consequently also to its presuppositions time and space) an _absolute_ existence, _i.e._, an existence independent of the perceiving subject; this is its fundamental error. Then, if it will go honestly to work, it must leave the qualities inherent in the given materials, _i.e._, in the substances, together with the natural forces which manifest themselves in these, and finally also the vital force, unexplained, as unfathomable _qualitates occultæ_, and start from them; as physics and physiology actually do, because they make no claim to be the ultimate explanation of things. But just to avoid this, materialism—at least as it has hitherto appeared—has not proceeded honestly. It denies all those original forces, for it pretends and seems to reduce them all, and ultimately also the vital force, to the mere mechanical activity of matter, thus to manifestations of impenetrability, form, cohesion, impulsive power, inertia, gravity, &c., qualities which certainly have least that is inexplicable in themselves, just because they partly depend upon what is known _a priori_, consequently on the forms of our own intellect, which are the principle of all comprehensibility. But the intellect as the condition of all objects, and consequently of the whole phenomenal world, is entirely ignored by materialism. Its plan is now to refer everything qualitative to something merely quantitative, for it attributes the former to mere _form_ in opposition to _matter_ proper. To matter it leaves, of the properly _empirical_ qualities, only gravity, because it already appears as something quantitative, the only measure of the quantity of the matter. This path necessarily leads it to the fiction of atoms, which now become the material out of which it thinks to construct the mysterious manifestations of all original forces. But here it has really no longer to do with empirically _given_ matter, but with a matter which is not to be found _in rerum natura_, but is rather a mere abstraction of that real matter, a matter which would absolutely have no other than those mechanical qualities which, with the exception of gravity, can be pretty well construed _a priori_, just because they depend upon the forms of space, time, and causality, and consequently upon our