3
" It will be seen how there can be the idea of a special science, the *critique of pure reason* as it may be called. For reason is the faculty which supplies the *principles* of *a priori* knowledge. Pure reason therefore is that which contains the principles of knowing something entirely *a priori*. An *organon* of pure reason would be the sum total of the principles by which all pure *a priori* knowledge can be acquired and actually established. Exhaustive application of such an organon would give us a system of pure reason. But as this would be a difficult task, and as at present it is still doubtful whether indeed an expansion of our knowledge is possible here at all, we may regard a science that merely judges pure reason, its sources and limits, as the *propaedeutic* to the system of pure reason. In general, it would have to be called only a *critique*, not a *doctrine* of pure reason. Its utility, in regard to speculation, would only be negative, for it would serve only to purge rather than to expand our reason, and, which after all is a considerable gain, would guard reason against errors. I call all knowledge *transcendental* which deals not so much with objects as with our manner of knowing objects insofar as this manner is to be possible *a priori*. A system of such concepts would be called *transcendental philosophy*. But this is still, as a beginning, too great an undertaking. For since such a science must contain completely both analytic and synthetic *a priori* knowledge, it is, as far as our present purpose is concerned, much too comprehensive. We will be satisfied to carry the analysis only so far as is indispensably necessary in order to understand in their whole range the principles of *a priori* synthesis, with which alone we are concerned. This investigation, which properly speaking should be called only a transcendental critique but not a doctrine, is all we are dealing with at present. It is not meant to expand our knowledge but only to correct it, and to become the touchstone of the value, or lack of value, of all *a priori* knowledge. Such a critique is therefore the preparation, as far as possible, for a new organon, or, if this should turn out not to be possible, for a canon at least, according to which, thereafter, the complete system of a philosophy of pure reason, whether it serve as an expansion or merely as a limitation of its knowledge, may be carried out both analytically and synthetically. That such a system is possible, indeed that it need not be so comprehensive as to cut us off from the hope of completing it, may already be gathered from the fact that it would have to deal not with the nature of things, which is inexhaustible, but with the understanding which makes judgments about the nature of things, and with this understanding again only as far as its *a priori* knowledge is concerned. The supply of this *a priori* knowledge cannot be hidden from us, as we need not look for it outside the understanding, and we may suppose this supply to prove sufficiently small for us to record completely, judge as to its value or lack of value and appraise correctly. Still less ought we to expect here a critique of books and systems of pure reason, but only the critique of the faculty of pure reason itself. Only once we are in possession of this critique do we have a reliable touchstone for estimating the philosophical value of old and new works on this subject. Otherwise, an unqualified historian and judge does nothing but pass judgments upon the groundless assertions of others by means of his own, which are equally groundless. "
― Immanuel Kant , Critique of Pure Reason
7
" 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... "
― Immanuel Kant , Critique of Pure Reason
10
" [At the beginning of modern science], a light dawned on all those who study nature. They comprehended that reason has insight only into what it itself produces according to its own design; that it must take the lead with principles for its judgments according to constant laws and compel nature to answer its questions, rather than letting nature guide its movements by keeping reason, as it were, in leading-strings; for otherwise accidental observations, made according to no previously designed plan, can never connect up into a necessary law, which is yet what reason seeks and requires. Reason, in order to be taught by nature, must approach nature with its principles in one hand, according to which alone the agreement among appearances can count as laws, and, in the other hand, the experiments thought in accordance with these principles - yet in order to be instructed by nature not like a pupil, who has recited to him whatever the teacher wants to say, but like an appointed judge who compels witnesses to answer the questions he puts to them. Thus even physics owes the advantageous revolution in its way of thinking to the inspiration that what reason would not be able to know of itself and has to learn from nature, it has to seek in the latter (though not merely ascribe to it) in accordance with what reason itself puts into nature. This is how natural science was first brought to the secure course of a science after groping about for so many centuries. "
― Immanuel Kant , Critique of Pure Reason
15
" There is no freedom, but everything in the world takes place entirely according to nature....Transcendental freedom is therefore opposed to the law of causality, and represents such a connection of successive states of effective causes, that no unity of experience is possible with it. It is therefore an empty fiction of the mind, and not to be met with in any experience.
We have, therefore, nothing but nature, in which we must try to find the connection and order of cosmical events. Freedom (independence) from the laws of nature is no doubt a deliverance from restraint, but also from the guidance of all rules. For we cannot say that, instead of the laws of nature, laws of freedom may enter into the causality of the course of the world, because, if determined by laws, it would not be freedom, but nothing else but nature. Nature, therefore, and transcendental freedom differ from each other like legality and lawlessness. The former, no doubt, imposes upon the understanding the difficult task of looking higher and higher for the origin of events in the series of causes, because their causality is always conditioned. In return for this, however, it promises a complete and well-ordered unity of experience; while, on the other side, the fiction of freedom promises, no doubt, to the enquiring mind, rest in the chain of causes, leading him up to an unconditioned causality, which begins to act by itself, but which, as it is blind itself, tears the thread of rules by which alone a complete and coherent experience is possible. "
― Immanuel Kant , Critique of Pure Reason
20
" Two things fill the mind with every new and increasing wonder and awe, the oftener and the more steadily I reflect upon them: the starry heavens above me and the moral law within me. I do not merely conjecture them and seek them as if they were obscured in darkness or in the transcendent region beyond my horizon: I see them before me, and I connect them directly with the consciousness of my own existence. The starry heavens begin at the place I occupy in the external world of sense, and they broaden the connection in which I stand into an unbounded magnitude of worlds beyond worlds and systems of systems and into the limitless times of their periodic motion, their beginning and duration. The latter begins at my invisible self, my personality, and exhibits me in a world which has true infinity but which only the understanding can trace - a world in which I recognise myself as existing in a universal and necessary ( and not, as in the first case, only contingent) connection, and thereby also in connection with all those visible worlds. The former view of a countless multitude of worlds annihilates, as it were, my importance as an 'animal creature' which must give back to the planet (a mere speck in the universe) the matter fro which it came, matter which is for a little time endowed with vital force, we know not how. The latter, on the contrary, infinitely raises my worth as that of an 'intelligence' by my being a person in whom the moral law reveals to me a life independent of all animality and even of the whole world of sense, at least so far as it may be inferred from the final destination assigned to my existence by this law, a destination which is not restricted to the conditions and boundaries of this life but reaches into the infinite. "
― Immanuel Kant , Critique of Pure Reason
