To the endless number of possible aims of human action correspond as many Imperatives, directing merely how they are to be attained, without any question of their value; these are Imperatives of _Fitness_. To one real aim, existing necessarily for all rational beings, viz., Happiness, corresponds the Imperative of _Prudence_ (in the narrow sense), being assertory while hypothetical. The categorical Imperative, enjoining a mode of action for itself, and concerned about the form and principle of it, not its nature and result, is the Imperative of _Morality_. These various kinds of Imperatives, as influencing the will, may be distinguished as _Rules_ (of fitness), _Counsels_ (of prudence), _Commands_ or _Laws_ (of morality); also as _technical, pragmatical, moral_. Now, as to the question of the possibility of these different Imperatives--how they can be supposed able to influence or act upon the Will--there is in the first case no difficulty; in wishing an end it is necessarily implied that we wish the indispensable means, when this is in our power. In like manner, the Imperatives of Prudence are also _analytical_ in character (_i.e._, given by implication), if only it were possible to have a definite idea of the end sought, viz., happiness. But, in fact, with the elements of happiness to be got from experience at the same time that the idea requires an absolute whole, or maximum, of satisfaction now and at every future moment, no finite being can know precisely what he wants, or what may be the effect of any of his wishes. Action, on fixed principles, with a view to happiness, is, therefore, not possible; and one can only follow empirical directions, about Diet, Frugality, Politeness, &c., seen on the whole to promote it. Although, however, there is no certainty of causing happiness, and the Imperatives with reference thereto are mere counsels, they retain their character of analytical propositions, and their action on the will is not less possible than in the former case. To prove the possibility of the Imperative of morality is more difficult. As categorical, it presupposes nothing else to rest its necessity upon; while by way of experience, it can never be made out to be more than a prudential precept--_i.e._, a pragmatic or hypothetic principle. Its possibility must therefore be established _à priori_. But the difficulty will then appear no matter of wonder, when it is remembered (from the Critique of Pure Reason) how hard it is to establish synthetic propositions _à priori_.