The Dialectic of Pure Practical Reason in General

Pure reason always has its dialetic, whether it is considered in its speculative or its practical employment; for it requires the absolute totality of the 'conditions of what is given conditioned, and this can only be found in things in themselves. But as all conceptions of things in themselves must be referred to intuitions, and with us men these can never be other than sensible and hence can never enable us to know objects as things in themselves but only as appearances, and since the unconditioned can never be found in this chain of appearances which consists only of conditioned and conditions; thus from applying this rational idea of the totality of the conditions (in other words of the unconditioned) to appearances, there arises an inevitable illusion, as if these latter were things in themselves (for in the absence of a warning critique they are always regarded as such). This illusion would never be noticed as delusive if it did not betray itself by a conflict of reason with itself, when it applies to appearances its fundamental principle of presupposing the unconditioned to everything conditioned. By this, however, reason is compelled to trace this illusion to its source, and search how it can be removed, and this can only be done by a complete critical examination of the whole pure faculty of reason; so that the antinomy of the pure reason which is manifest in its dialectic is in fact the most beneficial error into which human reason could ever have fallen, since it at last drives us to search for the key to escape from this labyrinth; and when this key is found, it further discovers that which we did not seek but yet had need of, namely, a view into a higher and an immutable order of things, in which we even now are, and in which we are thereby enabled by definite precepts to continue to live according to the highest dictates of reason.

Pure reason always has its dialectic, whether used for theoretical or practical purposes. It seeks the absolute totality of the conditions for whatever is given as conditioned. But this totality can be found only in things in themselves. All concepts of things in themselves must be related to intuitions. For us humans, these intuitions can only be sensory. So they can never enable us to know objects as things in themselves, but only as appearances. The unconditioned can never be found in this chain of appearances, which consists only of things conditioned and their conditions. When we apply reason’s idea of the totality of conditions, or the unconditioned, to appearances, an unavoidable illusion arises. It is as if appearances were things in themselves. Without a warning from critique, we always regard them as such. We would never recognize this illusion as deceptive if it did not reveal itself through reason’s conflict with itself. This conflict arises when reason applies its basic principle to appearances and assumes that everything conditioned has something unconditioned behind it. The conflict forces reason to trace the illusion to its source and find out how to remove it. This can be done only through a complete critical examination of the whole faculty of pure reason. The antinomy of pure reason, which appears in its dialectic, is therefore the most beneficial error human reason could ever have made. It finally drives us to look for a key to escape this labyrinth. When we find the key, it also reveals something we did not seek but nevertheless needed: a view of a higher and unchanging order of things. We already exist in this order, and the view enables us, through definite precepts, to continue living in it according to reason’s highest dictates.

It may be seen in detail in the Critique of Pure Reason how in its speculative employment this natural dialectic is to be solved, and how the error which arises from a very natural illusion may be guarded against. But reason in its practical use is not a whit better off. As pure practical reason, it likewise seeks to find the unconditioned for the practically conditioned (which rests on inclinations and natural wants), and this is not as the determining principle of the will, but even when this is given (in the moral law) it seeks the unconditioned totality of the object of pure practical reason under the name of the summum bonum.

The Critique of Pure Reason explains in detail how to resolve this natural dialectic in reason’s speculative use. It also explains how to guard against the error that arises from a very natural illusion. But reason is no better off in its practical use. As pure practical reason, it also seeks the unconditioned for what is practically conditioned (what depends on inclinations and natural wants). It does not seek the unconditioned as the principle that determines the will. Rather, even when that principle is given in the moral law, reason seeks the unconditioned totality of its object. It calls this totality the summum bonum.

To define this idea practically, i.e., sufficiently for the maxims of our rational conduct, is the business of practical wisdom, and this again as a science is philosophy, in the sense in which the word was understood by the ancients, with whom it meant instruction in the conception in which the summum bonum was to be placed, and the conduct by which it was to be obtained. It would be well to leave this word in its ancient signification as a doctrine of the summum bonum, so far as reason endeavours to make this into a science. For on the one hand the restriction annexed would suit the Greek expression (which signifies the love of wisdom), and yet at the same time would be sufficient to embrace under the name of philosophy the love of science: that is to say, of all speculative rational knowledge, so far as it is serviceable to reason, both for that conception and also for the practical principle determining our conduct, without letting out of sight the main end, on account of which alone it can be called a doctrine of practical wisdom. On the other hand, it would be no harm to deter the self-conceit of one who ventures to claim the title of philosopher by holding before him in the very definition a standard of self-estimation which would very much lower his pretensions. For a teacher of wisdom would mean something more than a scholar who has not come so far as to guide himself, much less to guide others, with certain expectation of attaining so high an end: it would mean a master in the knowledge of wisdom, which implies more than a modest man would claim for himself. Thus philosophy as well as wisdom would always remain an ideal, which objectively is presented complete in reason alone, while subjectively for the person it is only the goal of his unceasing endeavours; and no one would be justified in professing to be in possession of it so as to assume the name of philosopher who could not also show its infallible effects in his own person as an example (in his self-mastery and the unquestioned interest that he takes pre-eminently in the general good), and this the ancients also required as a condition of deserving that honourable title.

Practical wisdom aims to define this idea in practical terms, well enough to guide the principles of our rational conduct. As a science, practical wisdom is philosophy, in the sense the ancients gave that word. For them, philosophy meant instruction in what the summum bonum, or highest good, consists in and how to attain it. It would be good to keep this ancient meaning of philosophy: a doctrine of the summum bonum, insofar as reason seeks to make it a science. On the one hand, this qualification would fit the Greek expression, which means the love of wisdom. At the same time, it would allow philosophy to include the love of science. Here, science means all speculative rational knowledge, insofar as it helps reason understand the summum bonum and determine the practical principle that guides our conduct. This would keep the main goal in view, since only because of that goal can philosophy be called a doctrine of practical wisdom. On the other hand, it would do no harm to discourage the self-importance of someone who dares to call himself a philosopher. The definition itself would offer him a standard for judging himself that would greatly reduce his claims. A teacher of wisdom would be more than a scholar who has not yet learned to guide himself with a sure expectation of reaching so high a goal, much less to guide others. A teacher of wisdom would be a master of the knowledge of wisdom, which is more than a modest person would claim to be. Philosophy, like wisdom, would therefore always remain an ideal. Objectively, the ideal is complete in reason alone. Subjectively, for each person, it is only the goal of unceasing effort. No one would be justified in claiming to possess it and calling himself a philosopher unless he could also show its unfailing effects in his own life. He would have to set an example through self-mastery and an unquestionable concern for the general good above all else. The ancients, too, required this as a condition for deserving that honorable title.

We have another preliminary remark to make respecting the dialectic of the pure practical reason, on the point of the definition of the summum bonum (a successful solution of which dialectic would lead us to expect, as in case of that of the theoretical reason, the most beneficial effects, inasmuch as the self-contradictions of pure practical reason honestly stated, and not concealed, force us to undertake a complete critique of this faculty).

We have another preliminary remark about the dialectic of pure practical reason, concerning the definition of the summum bonum. Successfully resolving this dialectic would lead us to expect the greatest benefits, just as resolving the dialectic of theoretical reason would. For when the self-contradictions of pure practical reason are honestly stated rather than concealed, they force us to undertake a complete critique of this faculty.

The moral law is the sole determining principle of a pure will. But since this is merely formal (viz., as prescribing only the form of the maxim as universally legislative), it abstracts as a determining principle from all matter that is to say, from every object of volition. Hence, though the summum bonum may be the whole object of a pure practical reason, i.e., a pure will, yet it is not on that account to be regarded as its determining principle; and the moral law alone must be regarded as the principle on which that and its realization or promotion are aimed at. This remark is important in so delicate a case as the determination of moral principles, where the slightest misinterpretation perverts men's minds. For it will have been seen from the Analytic that, if we assume any object under the name of a good as a determining principle of the will prior to the moral law and then deduce from it the supreme practical principle, this would always introduce heteronomy and crush out the moral principle.

The moral law alone determines a pure will. But the moral law is purely formal. That is, it prescribes only that a maxim have the form of a universal law. As a determining principle, then, it leaves aside all matter, meaning every object of the will. So, although the highest good may be the whole object of pure practical reason, or a pure will, it is not therefore the principle that determines the will. Rather, the moral law alone must be regarded as the principle for aiming at the highest good and its realization or promotion. This point is important in so delicate a matter as determining moral principles, where the slightest misunderstanding distorts people’s thinking. For the Analytic has shown what happens if we assume that any object called good determines the will before the moral law does. If we then derive the supreme practical principle from that object, we always introduce heteronomy and destroy the moral principle.

It is, however, evident that if the notion of the summum bonum includes that of the moral law as its supreme condition, then the summum bonum would not merely be an object, but the notion of it and the conception of its existence as possible by our own practical reason would likewise be the determining principle of the will, since in that case the will is in fact determined by the moral law which is already included in this conception, and by no other object, as the principle of autonomy requires. This order of the conceptions of determination of the will must not be lost sight of, as otherwise we should misunderstand ourselves and think we had fallen into a contradiction, while everything remains in perfect harmony.

However, suppose the idea of the summum bonum includes the moral law as its supreme condition. Then the summum bonum would clearly be more than just an object. The idea of it, together with the thought that our own practical reason could make it possible, would also determine the will. This is because the moral law is already included in the idea of the summum bonum. The will is therefore determined by the moral law and not by any other object, as the principle of autonomy requires. We must keep this order of ideas about what determines the will in mind. Otherwise, we might misunderstand ourselves and think we had fallen into a contradiction, even though everything remains in perfect harmony.