Chapter 4. The History of Pure Reason

This title stands here merely to designate a place that is left vacant in the system and will have to be supplied at some future point. I content myself with casting, from a purely transcendental vantage point—namely the nature of pure reason—a fleeting glance over the whole of the treatments it has so far received, which to my eye admittedly presents edifices, yet only ones lying in ruins.

It is remarkable enough—though in the nature of things it could not have been otherwise—that human beings, in the childhood of philosophy, set out from precisely where we would now rather come to rest, namely by first taking up the cognition of God, together with the hope—or even the makeup—of a world beyond. Whatever crude religious concepts the ancient usages, surviving from a time even prior to the peoples' rude condition, may have brought in, this did not keep the more enlightened part from dedicating themselves to free inquiry into this object, and it was easy to see that no more solid and trustworthy way of pleasing the invisible power that rules the world—so as to be happy at least in another world—could be found than a good conduct of life. Theology and morals were on that account the two mainsprings—or better, the two points of reference—for all those abstracted inquiries of reason to which people have ever since given themselves. The former, meanwhile, was really what drew merely speculative reason, little by little, into that business which subsequently grew so famous under the title of metaphysics.

I will not now separate out the periods on which this or that transformation of metaphysics happened to fall, but only present, in a rapid outline, the difference of idea that prompted its principal revolutions. And there I find a threefold aim under which the most significant transformations were founded upon this stage of controversy.

1. As regards the object to which all our cognitions of reason refer, some were merely sensual-, others merely intellectual philosophers. Epicurus can be called the foremost philosopher of sensibility, Plato that of the intellectual realm. This distinction between the schools, however subtle it may be, dates back to the very earliest times and long persisted without a break. The adherents of the former maintained that actuality resides solely in the objects of the senses and that all the rest is fancy; the adherents of the second held, on the contrary: within the senses nothing is found but semblance, and the understanding alone cognizes what is true. On that account the former did not, for all that, deny reality to the concepts of the understanding, yet in their hands this reality was only logical, while in the hands of the others it was mystical. The former, while granting intellectual concepts, took only sensible objects to be given. The latter, by contrast, held the true objects to be merely intelligible and posited an intuition carried out through the pure understanding—one attended by no senses and, on their view, only thrown into confusion by them.

2. As concerns the origin of pure cognitions of reason—as to whether they are drawn from experience or, independently of it, find their source in reason. Aristotle can be taken as the leader of the empiricists, and Plato as that of the noologists. Locke, who in more recent days took the side of the former, and Leibniz, who took that of the latter (albeit at a sufficient distance from the latter's mystical system), have all the same proved unable to bring this quarrel to any decision. At least Epicurus, for his part, went about his sensual system far more consistently (for in his inferences he never once passed beyond the frontier of experience) than did Aristotle and Locke (but above all the latter), who, having drawn every concept and principle from experience, presses their use so far as to hold that God's existence and the immortality of the soul (although both objects lie wholly beyond the limits of possible experience) can be demonstrated every bit as evidently as some theorem of mathematics.

3. As to method. If anything at all is to bear the name of method, it must be a procedure conducted according to principles. Now the method presently dominant in this branch of investigation admits of a division into the naturalistic and the scientific. The naturalist where pure reason is concerned adopts as his principle: that on the loftiest questions making up the task of metaphysics more is to be achieved by ordinary reason without science (which he styles sound reason) than by way of speculation. He thus asserts that the size and remoteness of the moon can be settled with more assurance by the estimate of the eye than through mathematical detours. It is sheer misology raised to principles and—what is more preposterous than anything—the disregard of all artful means, trumpeted as a distinctive method for broadening one's cognition. For as far as those naturalists are concerned who act from a want of fuller insight, nothing can with good ground be charged against them. They keep to ordinary reason without parading their ignorance as a method that is supposed to hold the secret of drawing truth up from Democritus's deep well. Quod sapio, satis est mihi, non ego curo esse quod Arcesilas aerumnosique Solones (Pers.) is their watchword, under which they may, content and worthy of approval, pass their days without troubling over science or throwing its business into disarray.

As for those who observe a scientific method, they are here free to proceed either dogmatically or skeptically, though under every circumstance bound to proceed systematically. If for the first of these I here name the celebrated Wolff, and for the second David Hume, I may, consistent with my present aim, leave the others unnamed. The critical path alone still lies open. If the reader has shown the good will and patience to walk through it in my company, he may now judge whether—should he care to add his own contribution toward turning this footpath into a highroad—what many centuries were unable to accomplish might not be reached before the present one has run its course: that is, to grant human reason full contentment in the very matter that has forever engaged its craving to know, though thus far to no avail.