CHAPTER I. Of a Dialectic of Pure Practical Reason Generally. Pure reason always has its dialetic, whether it is considered in itsspeculative or its practical employment; for it requires theabsolute totality of the 'conditions of what is given conditioned, andthis can only be found in things in themselves. But as all conceptionsof things in themselves must be referred to intuitions, and with usmen these can never be other than sensible and hence can neverenable us to know objects as things in themselves but only asappearances, and since the unconditioned can never be found in thischain of appearances which consists only of conditioned andconditions; thus from applying this rational idea of the totality ofthe conditions (in other words of the unconditioned) to appearances,there arises an inevitable illusion, as if these latter were things inthemselves (for in the absence of a warning critique they are alwaysregarded as such). This illusion would never be noticed as delusive ifit did not betray itself by a conflict of reason with itself, whenit applies to appearances its fundamental principle of presupposingthe unconditioned to everything conditioned. By this, however,reason is compelled to trace this illusion to its source, and searchhow it can be removed, and this can only be done by a completecritical examination of the whole pure faculty of reason; so thatthe antinomy of the pure reason which is manifest in its dialecticis in fact the most beneficial error into which human reason couldever have fallen, since it at last drives us to search for the keyto escape from this labyrinth; and when this key is found, itfurther discovers that which we did not seek but yet had need of,namely, a view into a higher and an immutable order of things, inwhich we even now are, and in which we are thereby enabled by definiteprecepts to continue to live according to the highest dictates ofreason.
It may be seen in detail in the Critique of Pure Reason how in itsspeculative employment this natural dialectic is to be solved, and howthe error which arises from a very natural illusion may be guardedagainst. But reason in its practical use is not a whit better off.As pure practical reason, it likewise seeks to find theunconditioned for the practically conditioned (which rests oninclinations and natural wants), and this is not as the determiningprinciple of the will, but even when this is given (in the morallaw) it seeks the unconditioned totality of the object of purepractical reason under the name of the summum bonum.
To define this idea practically, i.e., sufficiently for the maximsof our rational conduct, is the business of practical wisdom, and thisagain as a science is philosophy, in the sense in which the word wasunderstood by the ancients, with whom it meant instruction in theconception in which the summum bonum was to be placed, and the conductby which it was to be obtained. It would be well to leave this word inits ancient signification as a doctrine of the summum bonum, so far asreason endeavours to make this into a science. For on the one hand therestriction annexed would suit the Greek expression (which signifiesthe love of wisdom), and yet at the same time would be sufficient toembrace under the name of philosophy the love of science: that is tosay, of all speculative rational knowledge, so far as it isserviceable to reason, both for that conception and also for thepractical principle determining our conduct, without letting out ofsight the main end, on account of which alone it can be called adoctrine of practical wisdom. On the other hand, it would be no harmto deter the self-conceit of one who ventures to claim the title ofphilosopher by holding