Immanuel Kant, Groundwork for the Metaphysics of Morals
Transition from Popular Moral Philosophy to the Metaphysics of Morals
The purpose of the second section is establish a move from a popular morality to one that is isolated from experience and knowledge of human nature—to a metaphysics of morals (Ak4:410). Because popular morality cannot be brought under any principle, it can only contingently lead us to good, and also to evil (Ak4:411). Thus, a metaphysics of morals is required to not only for a theoretical base of duties, but also for the actual fulfillment of its precepts (Ak4:410). For Kant, all moral concepts have their origin a priori to reason, and as such, cannot be taken from empirical cognition (Ak4:411). It is impossible to determine through experience whether the maxim of a dutiful action was solely out of duty, and thus of moral worth, or out of some covert incentive, such as self-love (Ak4:407). But regardless whether moral acts actually occur, reason commands what ought to happen, and therefore pure moral action can be demanded of every rational being, since reason determines the will through a priori grounds—laws are not based under contingent conditions and with exceptions—to be valid for all rational beings (Ak4:408). Hence, moral laws need to be expounded first as pure philosophy before it can be applied to human beings (Ak4:412).
Everything in nature works in accordance with laws (Ak4:412). If reason determines a will, whether with or without exception, then the command of reason, formulated into an imperative, can bring about a will into accordance with that law of morality as a practical good (Ak4:413). The imperative represents the practical rule in relation to a will that does not directly do an action because it is good (Ak4:414). The categorical imperative represents an action as objectively necessary for itself, and thus carries with it a universally valid necessity that ought to be obeyed, qualifying it to be the imperative of morality (Ak4:416). The imperative must be universal in scope, and the maxim in accordance with the imperative must be what the imperative represents necessarily (Ak4:420). Kant formulates the categorical imperative as follows: “Act only in accordance with that maxim through which you can at the same time will that it becomes a universal law” (Ak4:421). One must be able to will that a maxim of our action should become a universal law; the action must be thought of without contradiction as a universal law of nature and be possible to will without the will contradicting itself (Ak4:424). It is from this imperative that all imperatives of duty are derived. Perfect duty is construed as such that it permits no exception to incentive but always follows in accordance with the command of reason (Ak4:421). The transgression of duty results in rendering the maxim of the imperative into a general validity because through inclination to achieve some other aims, one desires to make an exception for oneself against the precept of reason (Ak4:424).
How does a will relate to the willing of a maxim as a universal law? Kant states that rational beings have the faculty to act in accordance with the representation of laws; they have a will (Ak4:412). In order for an act to be morally good, the will, out of necessity, must be brought into accordance with reason. A practical good determines the will from grounds that are valid for every rational being. This is in contrast to goods that have influence on the will only out of incentive not valid for everyone (Ak4:413). Since human will does not directly do an action because it is good, it requires an imperative that represents the practical rule in relation to it (Ak4:414). There would be no need for imperatives if the human will was a perfectly good will, the volition is of itself already necessarily in harmony with the law (Ak4:414). Kant restates the universal imperative of duty as: “So act as if the maxim of your action were to become through your will a universal law of nature” (Ak4:421). But in order to will it as such, the will of a rational being must be a “faculty of choosing only that which reason, independently of inclination, recognizes as practically necessary” (Ak4:12) to be certain that a maxim can be established as a categorical imperative. However, rational beings require such imperatives to bring the will in accordance with reason. This leads to the difficulty of knowing for certain that it is categorical and unconditioned, and not some pragmatic precept that we should pay attention to (Ak4:419) due to an impure will establishing imperatives for itself.