Chapter I (part 2)

But such a procedure constitutes a departure from facts, and all such considerations of the world and of the self, to the ordinary non-philosophical mind, will not have the character of obviousness. On the contrary the sole obvious fact remains the antithesis of I and Not-I —our inner psychic life and the outer world., Further on we shall return to this fundamental thesis. But thus far we have no basis on which to found a contradiction of the obvious fact of the existence of ourselves —i.e., of our inner life—and of the world in which we live. This we shall therefore accept as the given . This however is the only thing that we have the right to accept as p. 13 given: all the rest demands proof and definition in terms of these two given data. Space , with its extension; time , with the idea of before , now , after ; quantity, mass, substantiality; number, equality and inequality; identity and difference; cause and effect; the ether, atoms, electrons, energy, life, death—all things that form the foundation of our so-called knowledge: these are the unknown things . The existence in us of psychic life, i.e., of sensations, perceptions, conceptions, reasoning, feeling, desires etc., and the existence of the world outside of us—from these two fundamental data immediately proceed our common and clearly understood division of everything that we know into subjective and objective . Everything that we accept as a property of the world, we call objective; and everything that we accept as a property of our psyche, we call subjective. The subjective world we recognize directly : it is in ourselves—we are one with it. The objective world we picture to ourselves as existing somewhere outside of us—we and it are different things. It seems to us that if we should close our eyes, then the objective world would continue to exist, such as we just saw it; and if our inner life were to disappear, so would the subjective world disappear—yet the objective world would exist as before, as it existed at the time when we were not; when our subjective world was not. Our relation to the objective world is most exactly defined by the fact that we perceive it as existing in time and space ; otherwise, out of these conditions, we can neither conceive nor imagine it. In general, we say that the objective world consists of things and phenomena, i.e., things and changes in states of things. The PHENOMENA exist for us in time; the THINGS, in space. But such a division of the subjective and the objective world does not satisfy us. By means of reasoning we can establish the fact that in reality we know only our own sensations, perceptions and conceptions, and we cognize the objective world by projecting outside of ourselves the causes of our sensations, presupposing them to contain these causes. Then we find that our knowledge of the subjective world, and of p. 14 the objective world also, can be true and false , correct and incorrect. The criterion for the definition of correctness or incorrectness of our knowledge of the subjective world is the form of the relations of one sensation to others, and the force and character of the sensation itself . In other words, the correctness of one sensation is verified by the comparison of it with another of which we are more sure, or by the intensity and "taste" of a given sensation . The criterion for the definition of correctness or incorrectness of our knowledge of the objective world is the very same . It seems to us that we define the things and phenomena of the objective world by means of comparing them among themselves; and we think we find the laws of their existence outside of us , and independent of our perception of them. But it is an illusion. We know nothing about things separately from us ; and we have no other means of verifying the correctness of our knowledge of the objective world than BY SENSATIONS.