The Critique of Practical Reason. Immanuel Kant

them all in a table in which all possible cases are exhausted, except the one formal principle; and thus we can show visibly that it is vain to look for any other principle than that now proposed. In fact all possible principles of determination of the will are either merely subjective, and therefore empirical, or are also objective and rational; and both are either external or internal.

      Practical Material Principles of Determination taken as the Foundation of Morality, are:

      {BOOK_1|CHAPTER_1 ^paragraph 105}

SUBJECTIVEEXTERNAL INTERNAL

      Education Physical feeling

      {BOOK_1|CHAPTER_1 ^paragraph 110}

      (Montaigne) (Epicurus)

      The civil Moral feeling

      Constitution (Hutcheson)

      (Mandeville)

      {BOOK_1|CHAPTER_1 ^paragraph 115}

OBJECTIVEINTERNAL EXTERNAL

      Perfection Will of God

      (Wolf and the (Crusius and other {BOOK_1|CHAPTER_1 ^paragraph 120} Stoics) theological Moralists)

      Those of the upper table are all empirical and evidently incapable of furnishing the universal principle of morality; but those in the lower table are based on reason (for perfection as a quality of things, and the highest perfection conceived as substance, that is, God, can only be thought by means of rational concepts). But the former notion, namely, that of perfection, may either be taken in a theoretic signification, and then it means nothing but the completeness of each thing in its own kind (transcendental), or that of a thing merely as a thing (metaphysical); and with that we are not concerned here. But the notion of perfection in a practical sense is the fitness or sufficiency of a thing for all sorts of purposes. This perfection, as a quality of man and consequently internal, is nothing but talent and, what strengthens or completes this, skill. Supreme perfection conceived as substance, that is God, and consequently external (considered practically), is the sufficiency of this being for all ends. Ends then must first be given, relatively to which only can the notion of perfection (whether internal in ourselves or external in God) be the determining principle of the will. But an end- being an object which must precede the determination of the will by a practical rule and contain the ground of the possibility of this determination, and therefore contain also the matter of the will, taken as its determining principle- such an end is always empirical and, therefore, may serve for the Epicurean principle of the happiness theory, but not for the pure rational principle of morality and duty. Thus, talents and the improvement of them, because they contribute to the advantages of life; or the will of God, if agreement with it be taken as the object of the will, without any antecedent independent practical principle, can be motives only by reason of the happiness expected therefrom. Hence it follows, first, that all the principles here stated are material; secondly, that they include all possible material principles; and, finally, the conclusion, that since material principles are quite incapable of furnishing the supreme moral law (as has been shown), the formal practical principle of the pure reason (according to which the mere form of a universal legislation must constitute the supreme and immediate determining principle of the will) is the only one possible which is adequate to furnish categorical imperatives, that is, practical laws (which make actions a duty), and in general to serve as the principle of morality, both in criticizing conduct and also in its application to the human will to determine it.

      I. Of the Deduction of the Fundamental Principles of Pure Practical Reason.

      {BOOK_1|CHAPTER_1 ^paragraph 125}

      This Analytic shows that pure reason can be practical, that is, can of itself determine the will independently of anything empirical; and this it proves by a fact in which pure reason in us proves itself actually practical, namely, the autonomy shown in the fundamental principle of morality, by which reason determines the will to action.

      It shows at the same time that this fact is inseparably connected with the consciousness of freedom of the will, nay, is identical with it; and by this the will of a rational being, although as belonging to the world of sense it recognizes itself as necessarily subject to the laws of causality like other efficient causes; yet, at the same time, on another side, namely, as a being in itself, is conscious of existing in and being determined by an intelligible order of things; conscious not by virtue of a special intuition of itself, but by virtue of certain dynamical laws which determine its causality in the sensible world; for it has been elsewhere proved that if freedom is predicated of us, it transports us into an intelligible order of things.

      Now, if we compare with this the analytical part of the critique of pure speculative reason, we shall see a remarkable contrast. There it was not fundamental principles, but pure, sensible intuition (space and time), that was the first datum that made a priori knowledge possible, though only of objects of the senses. Synthetical principles could not be derived from mere concepts without intuition; on the contrary, they could only exist with reference to this intuition, and therefore to objects of possible experience, since it is the concepts of the understanding, united with this intuition, which alone make that knowledge possible which we call experience. Beyond objects of experience, and therefore with regard to things as noumena, all positive knowledge was rightly disclaimed for speculative reason. This reason, however, went so far as to establish with certainty the concept of noumena; that is, the possibility, nay, the necessity, of thinking them; for example, it showed against all objections that the supposition of freedom, negatively considered, was quite consistent with those principles and limitations of pure theoretic reason. But it could not give us any definite enlargement of our knowledge with respect to such objects, but, on the contrary, cut off all view of them altogether.

      On the other hand, the moral law, although it gives no view, yet gives us a fact absolutely inexplicable from any data of the sensible world, and the whole compass of our theoretical use of reason, a fact which points to a pure world of the understanding, nay, even defines it positively and enables us to know something of it, namely, a law.

      {BOOK_1|CHAPTER_1 ^paragraph 130}

      This law (as far as rational beings are concerned) gives to the world of sense, which is a sensible system of nature, the form of a world of the understanding, that is, of a supersensible system of nature, without interfering with its mechanism. Now, a system of nature, in the most general sense, is the existence of things under laws. The sensible nature of rational beings in general is their existence under laws empirically conditioned, which, from the point of view of reason, is heteronomy. The supersensible nature of the same beings, on the other hand, is their existence according to laws which are independent of every empirical condition and, therefore, belong to the autonomy of pure reason. And, since the laws by which the existence of things depends on cognition are practical, supersensible nature, so far as we can form any notion of it, is nothing else than a system of nature under the autonomy of pure practical reason. Now, the law of this autonomy is the moral law, which, therefore, is the fundamental law of a supersensible nature, and of a pure world of understanding, whose counterpart must exist in the world of sense, but without interfering with its laws. We might call the former the archetypal world (natura archetypa), which we only know in the reason; and the latter the ectypal world (natura ectypa), because it contains the possible effect of the idea of the former which is the determining principle of the will. For the moral law, in fact, transfers us ideally into a system in which pure reason, if it were accompanied with adequate physical power, would produce the summum bonum, and it determines our will to give the sensible world the form of a system of rational beings.

      The least attention to oneself proves that this idea really serves as the model for the determinations of our will.

      When the maxim which I am disposed to follow in giving testimony is tested by the practical reason, I always consider what it would be if it were to hold as a universal law of nature. It is manifest that in this view it would oblige everyone to speak the truth. For it cannot hold as a universal law of nature that statements should be allowed to have the force of proof and yet to be purposely untrue. Similarly, the maxim which I adopt with respect to disposing freely of my life is at once determined, when I ask myself what it should be, in order that a system, of which it is the law, should maintain itself. It is obvious that in such a system no one could arbitrarily put an end to his own life, for such an arrangement