truth of a proposition has no bearing on philosophical doctrines so long as a contrary belief is present, a belief such as we exert toward the illusions of the world of reality when we make practical use of that world's perspective. The schemes of personal philosophy, such, for instance, as we find in Schopenhauer, are dealt with by Nietzsche in a single paragraph: "When I analyse the process that is expressed in the sentence, 'I think,' I find a whole series of daring assertions, the argumentative proof of which would be difficult, perhaps impossible: for instance, that it is I who think, that there must necessarily be something that thinks, that thinking is an activity and operation on the part of a being who is thought of as a cause, that there is an 'ego,' and finally, that it is already determined what is to be designated by thinking--that I _know_ what thinking is. For if I had not already decided within myself what it is, by what standard could I determine whether that which is just happening is not perhaps 'willing' or 'feeling'? In short, the assertion 'I think,' assumes that I _compare_ my state at the present moment with other states of myself which I know, in order to determine what it is: on account of this retrospective connection with further 'knowledge,' it has at any rate no immediate certainty for me." Thus the smug materialistic philosopher finds himself necessitated to fall back on purely metaphysical explanations for answers to the questions arising out of his definition of truth. Locke falls under a critical survey in this chapter. In answer to this thinker's theory regarding the origin of ideas, Nietzsche names the great cycles of philosophical systems and calls attention to the similarity of processes in such cycles. Furthermore, he shows that the foundations of all previous philosophies are discoverable in the new styles of contemporaneous thought. And in those national schools of philosophy conceived in languages which stem from the same origin, he finds an undeniable resemblance. All of which leads to a conclusion incompatible with Locke's theory. Nietzsche attacks the conclusions of the physicists, denying them any place in philosophy because their research consists solely in interpretations of natural laws in accordance with their own prejudices and beliefs. The theories which might be deduced from natural phenomena are not discoverable in their doctrines; their activities have consisted in twisting natural events to suit preconceived valuations.