In this way, too, Objective Ethics leads to Subjective Ethics. The objective judgment not only presupposes a subjective basis, but also finds some of its best objects in actions which spring from the same mental constitution which is the basis of the judgment. Here, the basis of mental constitution and the motive coincide; the ethical law demands the existence of the moral disposition by which it itself exists in the species. This Kant expresses in the assertion that it is a duty to possess conscience. Since the recognition of duties presupposes the existence of conscience, it might seem as if here were an argument in a circle. But that this is an illusion may be seen from the fact that the basis of ethical judgment and the motive do not necessarily coincide and that it is not necessarily an imperfection when they do not coincide. It may be necessary in some cases, in accordance with the principle of welfare, that other motives than the sense of duty shall guide the action; it may be necessary and healthful, for example, that in some cases man should be led by the instinct of self-preservation, or by an immediate sympathy, to labor for the welfare of others, and that conscience should not be aroused in every single act. It may even be a sign of perfection when actions that demand exertion and sacrifice are carried out without the intervention of a sense of duty. Indeed, mental drill in the end renders that which at first took place by means of a long psychological process of reflection and will, direct and without special consciousness of its reason. All Ethics is practical Idealism. All systems assume an end, and an end is not anything at present existing, but something which ought to be. All systems assume, therefore, strong feeling, impulse, and endeavor, combined with the image of that which is the object of the endeavor. But the ideal must have points of contact with actuality, so that at least an approach to it is practicable; it must be physically, psychologically, and historically possible.