It is the notions of good and evil that first determine an object of the will. They themselves, however, are subject to a practical rule of reason which, if it is pure reason, determines the will a priori relatively to its object. Now, whether an action which is possible to us in the world of sense, comes under the rule or not, is a question to be decided by the practical judgement, by which what is said in the rule universally (in abstracto) is applied to an action in concreto. But since a practical rule of pure reason in the first place as practical concerns the existence of an object, and in the second place as a practical rule of pure reason implies necessity as regards the existence of the action and, therefore, is a practical law, not a physical law depending on empirical principles of determination, but a law of freedom by which the will is to be determined independently on anything empirical (merely by the conception of a law and its form), whereas all instances that can occur of possible actions can only be empirical, that is, belong to the experience of physical nature; hence, it seems absurd to expect to find in the world of sense a case which, while as such it depends only on the law of nature, yet admits of the application to it of a law of freedom, and to which we can apply the supersensible idea of the morally good which is to be exhibited in it in concreto. Thus, the judgement of the pure practical reason is subject to the same difficulties as that of the pure theoretical reason. The latter, however, had means at hand of escaping from these difficulties, because, in regard to the theoretical employment, intuitions were required to which pure concepts of the understanding could be applied, and such intuitions (though only of objects of the senses) can be given a priori and, therefore, as far as regards the union of the manifold in them, conforming to the pure a priori concepts of the understanding as schemata. On the other hand, the morally good is something whose object is supersensible; for which, therefore, nothing corresponding can be found in any sensible intuition. Judgement depending on laws of pure practical reason seems, therefore, to be subject to special difficulties arising from this, that a law of freedom is to be applied to actions, which are events taking place in the world of sense, and which, so far, belong to physical nature.