For, in order to bring the principles of this critique into exercise as soon as possible, and to demonstrate their perfect even in the presence of the highest degree of dialectical illusion, the student ought to examine the assertions made on both sides of speculative questions step by step, and to test them by these principles.It cannot be a difficult task for him to show the fallacies inherent in these propositions, and thus he begins early to feel his own power of securing himself against the influence of such sophistical arguments, which must finally lose, for him, all their illusory power.
And, although the same blows which overturn the edifice of his opponent are as fatal to his own speculative structures, if such he has wished to rear; he need not feel any sorrow in regard to this seeming misfortune, as he has now before him a fair prospect into the practical region in which he may reasonably hope to find a more secure foundation for a rational system.
There is, accordingly, no proper polemic in the sphere of pure reason.Both parties beat the air and fight with their own shadows, as they pass beyond the limits of nature, and can find no tangible point of attack- no firm footing for their dogmatical conflict.
Fight as vigorously as they may, the shadows which they hew down, immediately start up again, like the heroes in Walhalla, and renew the bloodless and unceasing contest.
But neither can we admit that there is any proper sceptical employment of pure reason, such as might be based upon the principle of neutrality in all speculative disputes.To excite reason against itself, to place weapons in the hands of the party on the one side as well as in those of the other, and to remain an undisturbed and sarcastic spectator of the fierce struggle that ensues, seems, from the dogmatical point of view, to be a part fitting only a malevolent disposition.But, when the sophist evidences an invincible obstinacy and blindness, and a pride which no criticism can moderate, there is no other practicable course than to oppose to this pride and obstinacy similar feelings and pretensions on the other side, equally well or ill founded, so that reason, staggered by the reflections thus forced upon it, finds it necessary to moderate its confidence in such pretensions and to listen to the advice of criticism.But we cannot stop at these doubts, much less regard the conviction of our ignorance, not only as a cure for the conceit natural to dogmatism, but as the settlement of the disputes in which reason is involved with itself.On the contrary, scepticism is merely a means of awakening reason from its dogmatic dreams and exciting it to a more careful investigation into its own powers and pretensions.But, as scepticism appears to be the shortest road to a permanent peace in the domain of philosophy, and as it is the track pursued by the many who aim at giving a philosophical colouring to their contemptuous dislike of all inquiries of this kind, I think it necessary to present to my readers this mode of thought in its true light.
Scepticism not a Permanent State for Human Reason.
The consciousness of ignorance- unless this ignorance is recognized to be absolutely necessary ought, instead of forming the conclusion of my inquiries, to be the strongest motive to the pursuit of them.All ignorance is either ignorance of things or of the limits of knowledge.If my ignorance is accidental and not necessary, it must incite me, in the first case, to a dogmatical inquiry regarding the objects of which I am ignorant; in the second, to a critical investigation into the bounds of all possible knowledge.
But that my ignorance is absolutely necessary and unavoidable, and that it consequently absolves from the duty of all further investigation, is a fact which cannot be made out upon empirical grounds- from observation- but upon critical grounds alone, that is, by a thoroughgoing investigation into the primary sources of cognition.It follows that the determination of the bounds of reason can be made only on a priori grounds; while the empirical limitation of reason, which is merely an indeterminate cognition of an ignorance that can never be completely removed, can take place only a posteriori.In other words, our empirical knowledge is limited by that which yet remains for us to know.The former cognition of our ignorance, which is possible only on a rational basis, is a science;the latter is merely a perception, and we cannot say how far the inferences drawn from it may extend.If I regard the earth, as it really appears to my senses, as a flat surface, I am ignorant how far this surface extends.But experience teaches me that, how far soever I go, I always see before me a space in which I can proceed farther; and thus I know the limits- merely visual- of my actual knowledge of the earth, although I am ignorant of the limits of the earth itself.But if I have got so far as to know that the earth is a sphere, and that its surface is spherical, I can cognize a priori and determine upon principles, from my knowledge of a small part of this surface- say to the extent of a degree- the diameter and circumference of the earth; and although I am ignorant of the objects which this surface contains, I have a perfect knowledge of its limits and extent.
The sum of all the possible objects of our cognition seems to us to be a level surface, with an apparent horizon- that which forms the limit of its extent, and which has been termed by us the idea of unconditioned totality.To reach this limit by empirical means is impossible, and all attempts to determine it a priori according to a principle, are alike in vain.But all the questions raised by pure reason relate to that which lies beyond this horizon, or, at least, in its boundary line.
