The Critique of Practical Reason [12]
agreed as to what were the objects of their feelings of pleasure and pain, and also as to the means which they must employ to attain the one and avoid the other; still, they could by no means set up the principle of self-love as a practical law, for this unanimity itself would be only contingent. The principle of determination would still be only subjectively valid and merely empirical, and would not possess the necessity which is conceived in every law, namely, an objective necessity arising from a priori grounds; unless, indeed, we hold this necessity to be not at all practical, but merely physical, viz., that our action is as inevitably determined by our inclination, as yawning when we see others yawn. It would be better to maintain that there are no practical laws at all, but only counsels for the service of our desires, than to raise merely subjective principles to the rank of practical laws, which have objective necessity, and not merely subjective, and which must be known by reason a priori, not by experience (however empirically universal this may be). Even the rules of corresponding phenomena are only called laws of nature (e.g., the mechanical laws), when we either know them really a priori, or (as in the case of chemical laws) suppose that they would be known a priori from objective grounds if our insight reached further. But in the case of merely subjective practical principles, it is expressly made a condition that they rest, not on objective, but on subjective conditions of choice, and hence that they must always be represented as mere maxims, never as practical laws. This second remark seems at first sight to be mere verbal refinement, but it defines the terms of the most important distinction which can come into consideration in practical investigations.
IV. THEOREM II.
A rational being cannot regard his maxims as practical universal laws, unless he conceives them as principles which determine the will, not by their matter, but by their form only. By the matter of a practical principle I mean the object of the will. This object is either the determining ground of the will or it is not. In the former case the rule of the will is subjected to an empirical condition (viz., the relation of the determining idea to the feeling of pleasure and pain), consequently it can not be a practical law. Now, when we abstract from a law all matter, i.e., every object of the will (as a determining principle), nothing is left but the mere form of a universal legislation. Therefore, either a rational being cannot conceive his subjective practical principles, that is, his maxims, as being at the same time universal laws, or he must suppose that their mere form, by which they are fitted for universal legislation, is alone what makes them practical laws.
REMARK.
The commonest understanding can distinguish without instruction what form of maxim is adapted for universal legislation, and what is not. Suppose, for example, that I have made it my maxim to increase my fortune by every safe means. Now, I have a deposit in my hands, the owner of which is dead and has left no writing about it. This is just the case for my maxim. I desire then to know whether that maxim can also bold good as a universal practical law. I apply it, therefore, to the present case, and ask whether it could take the form of a law, and consequently whether I can by my maxim at the same time give such a law as this, that everyone may deny a deposit of which no one can produce a proof. I at once become aware that such a principle, viewed as a law, would annihilate itself, because the result would be that there would be no deposits. A practical law which I recognise as such must be qualified for universal legislation; this is an identical proposition and, therefore, self-evident. Now, if I say that my will is subject to a practical law, I cannot adduce my inclination (e.g., in the present case my avarice) as a principle of determination fitted to be a universal practical law; for this is so far from
IV. THEOREM II.
A rational being cannot regard his maxims as practical universal laws, unless he conceives them as principles which determine the will, not by their matter, but by their form only. By the matter of a practical principle I mean the object of the will. This object is either the determining ground of the will or it is not. In the former case the rule of the will is subjected to an empirical condition (viz., the relation of the determining idea to the feeling of pleasure and pain), consequently it can not be a practical law. Now, when we abstract from a law all matter, i.e., every object of the will (as a determining principle), nothing is left but the mere form of a universal legislation. Therefore, either a rational being cannot conceive his subjective practical principles, that is, his maxims, as being at the same time universal laws, or he must suppose that their mere form, by which they are fitted for universal legislation, is alone what makes them practical laws.
REMARK.
The commonest understanding can distinguish without instruction what form of maxim is adapted for universal legislation, and what is not. Suppose, for example, that I have made it my maxim to increase my fortune by every safe means. Now, I have a deposit in my hands, the owner of which is dead and has left no writing about it. This is just the case for my maxim. I desire then to know whether that maxim can also bold good as a universal practical law. I apply it, therefore, to the present case, and ask whether it could take the form of a law, and consequently whether I can by my maxim at the same time give such a law as this, that everyone may deny a deposit of which no one can produce a proof. I at once become aware that such a principle, viewed as a law, would annihilate itself, because the result would be that there would be no deposits. A practical law which I recognise as such must be qualified for universal legislation; this is an identical proposition and, therefore, self-evident. Now, if I say that my will is subject to a practical law, I cannot adduce my inclination (e.g., in the present case my avarice) as a principle of determination fitted to be a universal practical law; for this is so far from