I do not mean by this a criticism of books and systems, but a critical inquiry into the faculty of reason, with reference to the cognitions to which it strives to attain without the aid of experience; in other words, the solution of the question regarding the possibility or impossibility of metaphysics, and the determination of the origin, as well as of the extent and limits of this science.
All this must be done on the basis of principles.
This path- the only one now remaining- has been entered upon by me; and I flatter myself that I have, in this way, discovered the cause of- and consequently the mode of removing- all the errors which have hitherto set reason at variance with itself, in the sphere of non-empirical thought.I have not returned an evasive answer to the questions of reason, by alleging the inability and limitation of the faculties of the mind; I have, on the contrary, examined them completely in the light of principles, and, after having discovered the cause of the doubts and contradictions into which reason fell, have solved them to its perfect satisfaction.It is true, these questions have not been solved as dogmatism, in its vain fancies and desires, had expected; for it can only be satisfied by the exercise of magical arts, and of these I have no knowledge.But neither do these come within the compass of our mental powers; and it was the duty of philosophy to destroy the illusions which had their origin in misconceptions, whatever darling hopes and valued expectations may be ruined by its explanations.My chief aim in this work has been thoroughness; and I make bold to say that there is not a single metaphysical problem that does not find its solution, or at least the key to its solution, here.Pure reason is a perfect unity; and therefore, if the if the principle presented by it prove to be insufficient for the solution of even a single one of those questions to which the very nature of reason gives birth, we must reject it, as we could not be perfectly certain of its sufficiency in the case of the others.
While I say this, I think I see upon the countenance of the reader signs of dissatisfaction mingled with contempt, when he hears declarations which sound so boastful and extravagant; and yet they are beyond comparison more moderate than those advanced by the commonest author of the commonest philosophical programme, in which the dogmatist professes to demonstrate the ****** nature of the soul, or the necessity of a primal being.Such a dogmatist promises to extend human knowledge beyond the limits of possible experience; while Ihumbly confess that this is completely beyond my power.Instead of any such attempt, I confine myself to the examination of reason alone and its pure thought; and I do not need to seek far for the sum-total of its cognition, because it has its seat in my own mind.
Besides, common logic presents me with a complete and systematic catalogue of all the ****** operations of reason; and it is my task to answer the question how far reason can go, without the material presented and the aid furnished by experience.
So much for the completeness and thoroughness necessary in the execution of the present task.The aims set before us are not arbitrarily proposed, but are imposed upon us by the nature of cognition itself.
The above remarks relate to the matter of our critical inquiry.As regards the form, there are two indispensable conditions, which any one who undertakes so difficult a task as that of a critique of pure reason, is bound to fulfil.These conditions are certitude and clearness.
As regards certitude, I have fully convinced myself that, in this sphere of thought, opinion is perfectly inadmissible, and that everything which bears the least semblance of an hypothesis must be excluded, as of no value in such discussions.For it is a necessary condition of every cognition that is to be established upon a priori grounds that it shall be held to be absolutely necessary; much more is this the case with an attempt to determine all pure a priori cognition, and to furnish the standard- and consequently an example-of all apodeictic (philosophical) certitude.Whether I have succeeded in what I professed to do, it is for the reader to determine; it is the author's business merely to adduce grounds and reasons, without determining what influence these ought to have on the mind of his judges.But, lest anything he may have said may become the innocent cause of doubt in their minds, or tend to weaken the effect which his arguments might otherwise produce- he may be allowed to point out those passages which may occasion mistrust or difficulty, although these do not concern the main purpose of the present work.He does this solely with the view of removing from the mind of the reader any doubts which might affect his judgement of the work as a whole, and in regard to its ultimate aim.