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"But if all begins with experience, it does not follow that all springs up out of experience; for it may happen that even our empirical knowledge is composed of what is received from sensible impressions, and of what our own understanding, merely excited to action by the sensible impressions, supplies from itself; though we may not, indeed, till long practice has made us attentive to it, and skilful in separating it, be able to distinguish the latter element from the former.

"It is therefore, to say the least, a question demanding a closer investigation than it has heretofore received, and also a question not to be answered at a single glance, whether we really have any cognitions which are independent of all experience, and even of all sensible impressions. We may call these cognitions a priori, and distinguish them from the empirical cognitions, which have their origin a posteriori, that is, in experience.

"This expression, cognition a priori, is not sufficiently definite, to designate the complete sense of the proposed inquiry. For we are accustomed to say of many empirical cognitions, that they are possible a priori, because we do not derive them immediately from experience, but from a general rule, which rule, however, is itself borrowed from experience. Thus, we say of a man, who undermines the foundation of his house, that he may know a priori that it will fall, and that he has no occasion, in order to know that it will fall, to wait for actual experience of its falling. But he cannot know this wholly a priori; for it is only from experience that he can know that bodies are heavy, and therefore must needs fall, if that which upholds them be taken away.

"In our inquiry, we shall understand by cognitions a priori, not such as may be independent of this or that particular fact of experience, but such as are absolutely independent of all experience. To these are opposed empirical cognitions, or such as are possible only through experience. Our cognitions a priori are either pure or mixed. Only those are pure which have no empirical mixture. For example. Every change has a cause. This is a proposition a priori, but not pure; for the conception of change, which it contains, is derivable only from experience." pp. 1, 2.

From this, Kant proceeds to show that we are, even in our ordinary condition, in possession of cognitions a priori.

"It is necessary here to find a sure mark, or criterion, by which a pure cognition may be distinguished from an empirical cognition. Experience may, indeed, teach us that something

may be made in this or that way, but not that it could have been made in no other way. If, then, in the first place, we find a proposition, which, at the same time that it is conceived, is also conceived as necessary, it is a judgment a priori; and if, moreover, it is underivable from any other proposition, which is also conceived as necessary, it is absolutely a priori. In the second place, empirical judgments are never truly and strictly universal, but have, at most, only an assumed and a comparative universality, (through induction,) so that we can only say from experience, So far as we have hitherto observed we have discovered no exception to this or that rule. A judgment, then, which is conceived as strictly universal, that is, as admitting no exception to be possible, cannot be derived from experience, but must be absolutely a priori. Empirical universality is only an arbitrary extension of validity, is merely a conclusion from what is true in most cases to what is true in all, as in this proposition, — All bodies are heavy. On the contrary, when strict universality belongs to a judgment, that universality shows that the judgment has a peculiar origin, namely, in the power of cognition a priori. Necessity and strict universality are, then, the certain marks of a cognition a priori, and they belong inseparably to each other. But since. it is sometimes easier to show the empirical limitation than the contingency of the judgment, or since the absolute universality which we attribute to a judgment is frequently more obvious than its necessity, it will be well to use these two criteria separately, of which either is sufficient by itself alone.

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"That there are necessary, and, in the strictest sense, universal, and therefore pure, human cognitions a priori, it is not difficult to show. If we wish for an example from science, we may take the mathematical axioms; if an example from the common use of the understanding, we may take the proposition, Every change has a cause. In this last example, in point of fact, the conception of cause so obviously involves the conception of its necessary connexion with the effect, and of the strict universality of the rule, that the conception of cause would be wholly lost, if we should undertake, as Hume does, to derive it from the frequent association of that which follows with that which precedes, and from the habit which we thus acquire, (therefore possessing merely a subjective necessity,) of connecting our representations. Moreover, without recurrence to similar examples for proof, we might demonstrate that our cognitions really contain a priori principles, by demonstrating the absolute indispensableness of such principles to the possibility of experience. For whence could experience deduce its own

certainty, if all the rules according to which it proceeds were themselves empirical, and therefore contingent? We could in such case hardly receive them as first principles. But it suffices for our present purpose, to have indicated the pure use of the understanding as a fact, together with its criteria.

"But it is not merely in the judgments, but also in the conceptions, that a certain cognition a priori is evident. Abstract from your empirical conception of body, one by one, color, hardness, softness, weight, impenetrability, all that is empirical in the conception, and there still remains the space, which this body, that has now disappeared, occupied, and the absence of which it is not possible to conceive. In like manner, abstract from your empirical conception of some object, corporeal or incorporeal, all the properties which you have learned from experience, you must still leave it the quality by which you conceive of it as substance, or as pertaining to substance (though this conception of substance is more definite than that of object in general). The necessity, therefore, with which this conception forces itself upon you, obliges you to confess that it has its seat in the understanding." - pp. 2–5.

All actual knowledge begins with experience, and prior to experience there is no actual knowledge; but every actual cognition, or fact of experience, if we understand Kant, is composed of two parts, one empirical, obtained from the sensible impression, the other a priori, furnished by the understanding itself from its own resources. The marks or criteria of the cognition a priori are universality and necessity. Whatever is conceived of as absolutely universal and necessary is a priori. The cognition a priori makes up one part of every actual cognition. Into every actual cognition or fact of experience, as the absolutely indispensable grounds and conditions of its possibility, enter, then, the conceptions of the universal and the necessary. This means, if we comprehend it, all simply, that we never do, and never can, conceive of the particular and contingent, save through conception of the universal and the necessary. This fact we are not disposed to question; but the further statement which Kant makes is not quite so evident, namely, that the conceptions of the universal and necessary are underivable from experience, and must, therefore, be cognitions a priori. Whence his proof, that, in

apprehending the particular and contingent, we do not also apprehend, as real objects, the universal and necessary, instead of supplying them from our own inneity?

But we must let Kant speak yet longer for himself. Having assumed that there are cognitions a priori, he proceeds to show that philosophy needs a science which determines their possibility, principles, and extent.

"What is still more important than what precedes is, that there are certain cognitions which leave entirely the field of even possible experience, and, through conceptions to which no objects in experience correspond, seem to extend the boundaries of science itself beyond the limits of experience. And it is precisely in these cognitions which transcend the sensible world, and in reference to which experience can neither guide us nor correct our judgments, that lie the most important investigations of our reason, investigations in our view altogether preferable to any thing the understanding can collect in the field of the understanding, and much sublimer in their aims, and which, therefore, we must needs prosecute at all hazards, even at the risk of error. No considerations of doubt, disregard, or indifference can induce us to abandon them. These unavoidable problems of the Pure Reason itself are, .GOD, FREEDOM, IMMORTALITY. But the science whose aims and preparations are directed solely to the solution of these problems, and which is called metaphysics, begins its process in dogmatism, and undertakes the solution with full confidence in itself, without having made any previous investigation of the ability or inability of reason to obtain it.

"It would, however, seem to be very natural, that, after having left the territory of experience, we should not proceed forthwith to construct a system with cognitions which we have obtained we know not whence, and on the strength of principles with whose origin we are unacquainted, or without having, by previous examination, fully assured ourselves of the solidity of the foundation; that we should rather ask the question, which should have been asked long ago, namely, How is the understanding able to attain to cognitions a priori, and what are their reach, their legitimacy, and their worth? Nothing, in fact, were more natural, if by natural we understand what is proper to be done; but if we understand by natural what usually happens, then nothing can be more natural, or easy to comprehend, than that this inquiry should have remained hitherto unattempted. For a part of this knowledge, namely, the mathematical, has from early times been in posses

sion of certainty, and by that fact created a favorable expectation of a like certainty in regard to the rest, notwithstanding the rest is of quite a different nature. Moreover, when once out beyond the circle of experience, we are sure of never being contradicted by experience. The charm of extending our cognitions is so great, that we will not, unless stumbling upon an evident contradiction, be restrained in our progress. But with proper care we can avoid contradiction in framing our fictions, and without their ceasing on that account to be fictions. The science of mathematics affords us a striking example of how far we may go in cognition a priori, without the aid of experience. This science, indeed, concerns itself with objects and cognitions, only so far as they may be intuitively represented; but this difficulty can be easily surmounted, for the intuition itself may be given a priori, and therefore be little else than mere conception. Captivated by this proof of the power of reason, the impulse to extension perceives no limits. The light dove, in her free flight in the air whose resistance she feels, may fancy that she would succeed all the better in airless space. So Plato left the sensible world because it set too narrow bounds to the understanding, and ventured forth on the wings of Ideas into the empty space of the pure understanding. He did not remark that he made no progress by his efforts, since he had no resisting medium to serve for his support, on which he could rest, and to which he could apply his strength to propel the understanding forward. But it is the usual fate of human speculation to prepare its edifice as soon as possible, and then, for the first time, to inquire whether its foundation has been well laid. Then are sought all kinds of excuses to console us for its want of fitness, or to put off so late and so dangerous an investigation. During the construction of the edifice, we are freed from care and suspicion, and flattered with an apparent solidity, by the fact, that a great part, perhaps the greatest part, of the business of our reason consists in the analysis of conceptions which we already possess of objects. We are thus supplied with a multitude of cognitions, which, though nothing but elucidations and explanations of what had already been conceived, but in a confused manner, are nevertheless esteemed, at least as to the form, to be new views, notwithstanding they do not extend the matter, or content, of our conceptions, but merely disentangle it. Now, since this analytic process furnishes us with a real cognition a priori, which has a sure and useful progression, the reason, as it were unconsciously, smuggles in along with it assertions of quite a different nature, and adds to given conceptions others,

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