Immanuel Kant's Critique of Pure Reason — trans. F. Max Müller

This we can only do by means of concepts which add something to a given concept that was not contained in it ; nay, we even attempt, by means of synthetical judgments a priori, to go so far beyond a given concept that experience itself cannot follow us : as, for instance, in the proposition that the world must have a first beginning. Thus, according at least to its intentions, metaphysic consists merely of synthetical propositions a priori.

VI The General Problem of Pure Reason

Much is gained if we are able to bring a number of investigations under the formula of one single problem. For we thus not only facilitate our own work by defining it accurately, but enable also everybody else who likes to examine it to form a judgment, whether we have really done justice to our purpose or not. Now the real problem of pure reason is contained in the question. How are synthetical judgments a "^xioxi possible ?

That metaphysic has hitherto remained in so vacillating a state of ignorance and contradiction is entirely due to people not having thought sooner of this problem, or perhaps even of a distinction between analytical and synthetical judgments. The solution of this problem, or a sufficient proof that a possibiHty which is to be explained does in reality not exist at all, is the question of life or death to metaphysic. David Hume, who among all philosophers approached nearest to that problem, though he was far from conceiving it with sufficient definiteness and universality, confining his attention only to the synthetical proposition of the connection of an effect with its causes {principium causalitatis) , arrived at the conclusion that such a proposition a priori is entirely impossible. According to his conclusions, everything which we call metaphysic would turn out to be a mere delusion of reason, fancying that it knows by itself what in reality is only borrowed from experience, and has assumed by mere habit the appearance of necessity. If he had grasped our problem in all its universality, he would never have thought of an assertion which

724 SiLppleinent VI destroys all pure philosophy, because he would have perceived that, according to his argument, no pure mathematical science was possible either, on account of its certainly containing synthetical propositions a priori; and from such an assertion his good sense would probably have saved him.

On the solution of our problem depends, at the same time, the possibility of the pure employment of reason, in establishing and carrying out all sciences which contain a theoretical knowledge a priori of objects, i.e. the answer to the questions

How is pure mathematical science possible ?

How is pure natural science possible ?

As these sciences really exist, it is quite proper to ask. How they are possible? for that they must be possible, is proved by their reality.^

But as to metaphysic, the bad progress which it has hitherto made, and the impossibiHty of asserting of any of the metaphysical systems yet brought forward that it really exists, so far as its essential aim is concerned, must fill every one with doubts as to its possibihty.

Yet, in a certain sense, this kind of knowledge also must be looked upon as given, and though not as a science, yet as a natural disposition {metaphysica naturalist metaphysic is real. For human reason, without being moved merely by the conceit of omniscience, advances irresistibly, and urged on by its own need, to questions such as cannot be answered by any empirical employment of reason, or by principles thence derived, so that we may really say, that all men, as soon as their reason became ripe for speculation, have at all times possessed some kind of metaphysic, and will always continue to possess it. And now it will also have to answer the question

1 One might doubt this with regard to pure natural science; but one has only to consider the different propositions which stand at the beginning of real (empirical) physical science, those, for example, relating to the permanence of the same quantity of matter to the vis ine7'Hae,ihe equality of action and reaction, etc., in order to become convinced that they constitute 2. physic a pur a, or rationalise which well deserves to stand by itself as an independent science, in its whole extent, whether narrow or wide.

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