V. The Act of Knowing the World

From the foregoing considerations it follows that by investigating the content of our observation it is impossible to prove that our perceptions are representations. This proof is supposed to follow from the fact that if the process of perception takes place in the way it is imagined, according to the naive-realistic suppositions as to man's psychological and physiological constitution, then we are dealing, not with things-in-themselves, but merely with our representations of things. Now if naive realism, when consistently thought through, leads to results which directly contradict what it presupposes, then one must regard its presuppositions as unsuitable for the foundation of a world view and discard them. It is certainly inadmissible on the one hand to reject the presuppositions and yet, on the other, to regard their outcome as valid, as does the critical idealist when he bases his assertion, The world is my representation, on the so-called proof indicated above. (Eduard von Hartmann gives a full account of this line of argument in his work, Das Grundproblem der Erkenntnistheorie, The Basic Problem of a Theory of Knowledge.)