Critique of Practical Reason - Analytic: Chapter One

Analytic: Chapter One

Practical reason is the faculty for determining the will, which operates by applying a general principle of action to one's particular situation. For Kant, a principle can be either a mere maxim if it is based on the agent's desires or a law if it applies universally. Any principle that presupposes a previous desire for some object in the agent always presupposes that the agent is the sort of person who would be interested in that particular object. Anything that an agent is interested in can only be contingent, however, and never necessary. Therefore it cannot be a law.

To say, for example, that the law is to serve God means that the law is dependent on interest in God. This cannot be the basis for any universal moral law. To say that the law is to seek the greatest happiness of the greatest number or the greatest good, always presupposes some interest in the greatest happiness, the greatest number, the greatest good, and so on. Kant concludes that the source of the nomological character of the moral law must derive not from its content but from its form alone. The content of the universal moral law, the categorical imperative, must be nothing over and above the law's form, otherwise it will be dependent on the desires that the law's possessor has. The only law whose content consists in its form, according to Kant, is the statement:

Kant then argues that a will which acts on the practical law is a will which is acting on the idea of the form of law, an idea of reason which has nothing to do with the senses. Hence the moral will is independent of the world of the senses, the world where it might be constrained by one's contingent desires. The will is therefore fundamentally free. The converse also applies: if the will is free, then it must be governed by a rule, but a rule whose content does not restrict the freedom of the will. The only appropriate rule is the rule whose content is equivalent to its form, the categorical imperative. To follow the practical law is to be autonomous, whereas to follow any of the other types of contingent laws (or hypothetical imperatives) is to be heteronomous and therefore unfree. The moral law expresses the positive content of freedom, while being free from influence expresses its negative content.

Furthermore, we are conscious of the operation of the moral law on us and it is through this consciousness that we are conscious of our freedom and not through any kind of special faculty. Though our actions are normally determined by the calculations of "self-love", we realize that we can ignore self-love's urgings when moral duty is at stake. Consciousness of the moral law is a priori and unanalysable.

Kant ends this chapter by discussing Hume's refutation of causation. Hume argued that we can never see one event cause another, but only the constant conjunction of events. Kant suggests that Hume was confusing the phenomenal and noumenal worlds. Since we are autonomous, Kant now claims that we can know something about the noumenal world, namely that we are in it and play a causal role in it. This knowledge, however, is only practical and not theoretical. Therefore it does not affect our knowledge of the things in themselves. Metaphysical speculation on the noumenal world is avoided.