A priori Quotes

“This experiment succeeds as hoped and promises to metaphysics, in its first part, which deals with those *a priori* concepts to which the corresponding objects may be given in experience, the secure course of a science. For by thus changing our point of view, the possibility of *a priori* knowledge can well be explained, and, what is still more, the laws which *a priori* lie at the foundation of nature, as the sum total of the objects of experience, may be supplied with satisfactory proofs, neither of which was possible within the procedure hitherto adopted. But there arises from this deduction of our faculty of knowing *a priori*, as given in the first part of metaphysics, a somewhat startling result, apparently most detrimental to that purpose of metaphysics which has to be treated in its second part, namely the impossibly of using this faculty to transcend the limits of possible experience, which is precisely the most essential concern of the science of metaphysics. But here we have exactly the experiment which, by disproving the opposite, establishes the truth of the first estimate of our *a priori* rational knowledge, namely, that it is directed only at appearances and must leave the thing in itself as real for itself but unknown to us. For that which necessarily impels us to to go beyond the limits of experience and of all appearances is the *unconditioned*, which reason rightfully and necessarily demands, aside from everything conditioned, in all things in themselves, so that the series of conditions be completed. If, then, we find that, under the supposition that our empirical knowledge conforms to objects as things in themselves, the unconditioned *cannot be thought without contradiction*, while under the supposition that our representation of things as they are given to us does not conform to them as things in themselves, but, on the contrary, that these objects as appearance conform to our mode of representation, then *the contradiction vanishes*; and if we find, therefore, that the unconditioned cannot be encountered in things insofar as we are acquainted with them (insofar as they are given to us), but only in things insofar as we are not acquainted with them, that is, insofar as they are things in themselves; then it becomes apparent that what we at first assumed only for the sake of experiment is well founded. However, with speculative reason unable to make progress in the field of the supersensible, it is still open to us to investigate whether in reason's practical knowledge data may not be found which would enable us to determine that transcendent rational concept of the unconditioned, so as to allow us, in accordance with the wish of metaphysics, to get beyond the limits of all possible experience with our *a priori* knowledge, which is possible in practical matters only. Within such a procedure, speculative reason has always at least created a space for such an expansion, even if it has to leave it empty; none the less we are at liberty, indeed we are summoned, to fill it, if we are able to do so, with practical *data* of reason."―from_Critique of Pure Reason_. Preface to the Second Edition. Translated, edited, and with an Introduction by Marcus Weigelt, based on the translation by Max Müller, pp. 19-21”

“A similar experiment may be tried in metaphysics as regards the *intuition* of objects. If the intuition had to conform to the constitution of objects, I would not understand how we could know anything of them *a priori*; but if the object (as object of the senses) conformed to the constitution of our faculty of intuition, I could very well conceive such a possibility. As, however, I cannot rest in these intuitions if they are to become knowledge, but have to refer them as representations, to something as their object, and must determine this object through them, I can assume either that the *concepts* through which I arrive at this determination also conform to the object, and I would again be as perplexed about how I can know anything about it *a priori*; or else that the objects, or what is the same thing, the *experience* in which alone they are known (as objects that are given to us), conform to those concepts. In the latter case, I recognize an easier solution because experience itself is a kind of knowledge that requires understanding; and this understanding has its rules which I must presuppose as existing within me even before objects are given to me, and hence *a priori*. These rules are expressed in *a priori* concepts to which all objects of experience must necessarily conform, and with which they must agree. With regard to objects, insofar as they are thought merely through reason and thought indeed as necessary, and which can never, at least not in the way in which reason thinks them, be given in experience, the attempts at thinking them (for they must admit of being thought) will subsequently furnish an excellent touchstone of what we are adopting as our new method of thought, namely, that we know of things *a priori* only that which we ourselves put into them."―from_Critique of Pure Reason_. Preface to the Second Edition. Translated, edited, and with an Introduction by Marcus Weigelt, based on the translation by Max Müller, pp. 18-19”

“It must be *possible* for the *I think* to accompany all my representations: for otherwise something would be represented within me that could not be thought at all, in other words, the representation would either be impossible, or at least would be nothing to me. That representation which can be given prior to all thought is called *intuition*, and all the manifold of intuition has, therefore, a necessary relation to the *I think* in the same subject in which this manifold of intuition is found. This representation (the *I think*), however, is an act of *spontaneity*, that is, it cannot be considered as belonging to sensibility. I call it *pure apperception*, in order to distinguish it from empirical apperception, as also from original apperception, because it is that self-consciousness which, by producing the representations, *I think* (which must be capable of accompanying all other representations, and which is one and the same in all consciousness), cannot itself be accompanied by any further representations. I also call the unity of apperception the *transcendental* unity of self-consciousness, in order to indicate that *a priori* knowledge can be obtained from it. For the manifold representations given in an intuition would not one and all be *my* representations, if they did not all belong to one self-consciousness. What I mean is that, as my representations (even though I am not conscious of them as that), they must conform to the condition under which alone they *can* stand together in one universal self-consciousness, because otherwise they would not one and all belong to me. From this original combination much can be inferred.The thoroughgoing identity of the apperception of a manifold that is given in intuition contains a synthesis of representations, and is possible only through the consciousness of this synthesis. For the empirical consciousness which accompanies different representations is itself dispersed and without reference to the identity of the subject. Such a reference comes about, not simply through my accompanying every representation with consciousness, but through my *adding* one representation to another and being conscious of the synthesis of them. Only because I am able to combine a manifold of given representations *in one consciousness* is it possible for me to represent to myself the *identity of the consciousness in these representations*, that is, only under the presupposition of some *synthetic* unity of apperception is the *analytic* unity of apperception possible. The thought that the representations given in intuition belong one and all *to me*, is therefore the same as the thought that I unite them in one self-consciousness, or can at least do so; and although that thought itself is not yet the consciousness of the synthesis of representations, it nevertheless presupposes the possibility of this synthesis. In other words, it is only because I am able to comprehend the manifold of representations in one consciousness that I call them one and all *my* representations. For otherwise I should have as many-coloured and varied a self as I have representations of which I am conscious. Synthetic unity of the manifold of intuitions, as given *a priori*, is thus the ground of the identity of apperception itself, which precedes *a priori* all *my* determinate thought. Combination, however, does not lie in the objects, and cannot be borrowed from them by perception and thus first be taken into the understanding. It is, rather, solely an act of the understanding, which itself is nothing but the faculty of combining *a priori* and of bringing the manifold of given representations under the unity of apperception; and the principle of this unity is, in fact, the supreme principle of all human knowledge."—from_Critique of Pure Reason_. Translated, edited, and with an Introduction by Marcus Weigelt, based on the translation by Max Müller, pp. 124-128”

“If it be true that there can be no metaphysics transcending human reason, it is no less true that there can be no empirical knowledge that is not already caught and limited by the a priori structure of cognition.”

“That all our knowledge begins with experience there can be no doubt. For how should the faculty of knowledge be called into activity, if not by objects which affect our senses and which, on the one hand, produce representations by themselves or on the other, rouse the activity of our understanding to compare, connect, or separate them and thus to convert the raw material of our sensible impressions into knowledge of objects, which we call experience? With respect to time, therefore, no knowledge within us is antecedent to experience, but all knowledge begins with it.But though all our knowledge begins with experience, is does not follow that it all arises from experience. For it is quite possible that even our empirical knowledge is a compound of that which we perceive through impressions, and of that which our own faculty of knowledge (incited by sense impressions) supplies from itself, a supplement which we do not distinguish from that raw material until long practice and rendered us capable of separating one from the other.It is therefore a question which deserves at least closer investigation and cannot be disposed of at first sight: Whether there is any knowledge independent of all experience and even of all impressions of the senses? Such knowledge is called 'a priori' and is distinguished from empirical knowledge, which has its source 'a posteriori', that is, in experience...”

“Among all the occurrences possible in the universe the a priori probability of any particular one of them verges upon zero. Yet the universe exists; particular events must take place in it, the probability of which (before the event) was infinitesimal. At the present time we have no legitimate grounds for either asserting or denying that life got off to but a single start on earth, and that, as a consequence, before it appeared its chances of occurring were next to nil. ... Destiny is written concurrently with the event, not prior to it... The universe was not pregnant with life nor the biosphere with man. Our number came up in the Monte Carlo game. Is it surprising that, like the person who has just made a million at the casino, we should feel strange and a little unreal?”

“Our critique is not opposed to the *dogmatic procedure* of reason in its pure knowledge as science (for science must always be dogmatic, that is, derive its proof from secure *a priori* principles), but only to *dogmatism*, that is, to the presumption that it is possible to make any progress with pure (philosophical) knowledge from concepts according to principles, such as reason has long been in the habit of using, without first inquiring in what way, and by what right, it has come to posses them. Dogmatism is therefore the dogmatic procedure of pure reason, *without a preceding critique of its own powers*; and our opposition to this is not intended to defend that loquacious shallowness which arrogates to itself the name of popularity, much less that skepticism which makes short work of the whole of metaphysics. On the contrary, our critique is meant to form a necessary preparation in support of metaphysics as a thorough science, which must necessarily be carried out dogmatically and strictly systematically, so as to satisfy all the demands, no so much of the public at large, as of the Schools. This is an indispensable demand for it has undertaken to carry out its work entirely *a priori*, and thus to carry it out to the complete satisfaction of speculative reason. In the execution of this plan, as traced out by the critique, that is, in a future system of metaphysics, we shall have to follow the strict method of the celebrated Wolff, the greatest of all dogmatic philosophers. He was the first to give an example (and by his example initiated, in Germany, that spirit of thoroughness which is not yet extinct) of how the secure course of a science could be attained only through the lawful establishment of principles, the clear determination of concepts, the attempt at strictness of proof and avoidance of taking bold leaps in our inferences. He was therefore most eminently qualified to give metaphysics the dignity of a science, if it had only occurred to him to prepare his field in advance by criticism of the organ, that is, of pure reason itself―an omission due not so much to himself as to the dogmatic mentality of his age, about which the philosophers of his own, as well as of all previous times, have no right to reproach one another. Those who reject both the method of Wolff and the procedure of the critique of pure reason can have no other aim but to shake off the fetters of *science* altogether, and thus to change work into play, certainty into opinion and philosophy into philodoxy." ―from_Critique of Pure Reason_. Preface to the Second Edition. Translated, edited, and with an Introduction by Marcus Weigelt, based on the translation by Max Müller, pp. 28-29”

“Any necessary truth, whether a priori or a posteriori, could not have turned out otherwise.”

“One basis for life and another basis for science is a priori a lie.”