Kant, incited by Hume's scepticism, undertook, in his Kritik der reinen Vernunft, a more thorough exam- ination of the origin, extent, and limits of human knowledge than had hitherto been given. Its object was to establish the distinction between phenomena and real things, or " things-in-themselves." The latter have a real objective existence, but out of relation to time, space, or causalitj', and hence out of the realm of all experience. He ascribes to these real tldngs the function of affecting the senses, and thus giving the material of thought or the substance of phenomena. In this was a realistic element, while in their indepen- dence of space and time there is an idealism (q. v.). As to phenomena, their substance is given through impres- sions on the senses, derived in some way from the things in themselves. But the forms under which we have a knowledge of these phenomena are a purely sub- jective product of the mind itself, by virtue of its spon- taneity. They are forms of intuition, viz. of space and time, and forms or categories of thought, twelve in number, such as unity, realitj', causality. As to the extent of our knowledge, in Kant's critique the things- in-themselves are unknowable for man. Only a crea- tive, divine mind, that gives them reality at the same time that it thinks them, can have power truly to know them ; they have neither unity nor plurality, nor sub- stantiality, nor are they subject to the causal relation, or to any of the categories of thought. We can luiow phenomena, but phenomena only. Tliey are the men- tal representations which exist in our consciousness, de- rived from the things in themselves by virtue of the function of these things to aifect our senses, but known under those forms of intuition and thought which are the purely spontaneous, subjective creations of the mind itself. These forms of our knowledge have their origin in certain corresponding a p}-iori judgments or cogni- tions, b}' which he means " those which take place in- dependently, not of this or that, but of all experience whatever." The certainty and truthfulness of all our knowledge depend upon the truthfulness and validity of these ii jn-iori judgments or cognitions. The criteria of the truthfulness of these judgments are necessity and strict universality, it being assumed, as the basis of his sj-stem of a priori knowledge, that necessity and strict universality are derivable from no combination of expe- riences, but only independently of all ex]ierience. All cognitions or propositions that have these marks are true. But it is to be borne in mind that our knowledge under these forms is true and objectiveh' valid, not in regard to things as they are in themselves, apart from our mode of conceiving them, but onlv in regard to em-
NIHILISM
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NIHILISM
pirical objects or the phenomena which exist in onr consciousness in the form of mental representations. In what we call external objects, Kant sees only mental representations resulting from the nature of onr sensi- bilitv. "The things which we perceive are not what we take them to be, nor their relations of such intrinsic nature as they appear to us to be ; if we make abstrac- tion of ourselves as knowing subjects, or even only of the subjective constitution of our senses generally, all the qualities, all the relations of objects in space and time, yes, and even space and time themselves, disap- pear : as phenomena they cannot really exist ;;e?- se, but only in us; what may be the character of things in themselves, and wholly separated from our receptive sensibility, remains wholly unknown to us." We can now perceive to what extent Kant in his philosophy had overcome nihilism. We have a true and valid knowledge of everything in our experience, in our con- sciousness. What is in our consciousness, the phenom- ena, is real, and we have a real and truthfid knowledge of it. Furthermore, there is a real objective existence of things, otherwise there would be no phenomena, and no objects of thought. But beyond this there is much of the ignorance and uncertainty of nihilism. For the forms under which our knowledge is possible are so purely subjective, so purely independent creations of the mind itself, that they bring all the objects or mate- rial of knowledge to the mind in their own form and features and dress, so that we cannot be certain that our knowledge corresponds to the reality of things. All knowledge is thus relafive to the human mind. It is conditional only, conditioned by those forms of the un- derstanding which mould it into the form in which it is received. As the a prio7-i judgments upon which all our knowledge is based arise from the constitution of the mind itself, a change in the constitution of the mind might involve a change in these fundamental a priori judgments and forms, and thus in the knowledge which is built upon them. They thus have for us a re(jxdutive force, but perhaps only a relative truth and vuUdity. Man must use them ; they are the condition and law of all his intellectual processes; but "he is not thereby authorized to assume that they hold good as the laws of minds which may be supposed to be constituted dif- ferently from those of human beings, or that they hold true of the knowledge which such beings acquire. On the one hand we cannot deny that they do hold true for other beings and their knowledge ; and on the other we cannot deny that they do not." In his most acute and thorough examination of the laws and operations of the human mind, and of the nature of our knowledge, Kant established more conclusively and firmly than had hitherto been done the fact, which lies at tlie basis of all true philosophy, of certain universal and necessary a priori or intuitive truths. But in assuming that these truths are the product of the mind's own creative ac- tivity, independent of all experience, he gave to all our knowledge an uncertain relativity, and introduced an element akin to nihilism. To this it has been very justly objected that these truths are not given inde- pendently of all experience, but are so connected with and derived from our experience of the external objec- tive world as to give us necessarily a truthful knowl- edge corresponding to the reality of things. Nor can the analogies derived from the senses, from such phe- nomena as the changes in the color of objects seen through differently colored glass, or occasioned by changes in the physical condition of the e3'e, be legit- imately applied to objects and acts of the pure reason. We are not justified in asserting that there may or might exist created or finite minds which know objects without the relations of time, space, and causalitj', or under relations entirely different. Moreover, it has been observed that such a possibility or probability is inconsistent with the use made of those very relations in establishing them as having a regulative and real existence in the mind itself; for in the creation of the