According to the principles of that ethical naturalism, there can be no _duty_ at all, no objective moral law, binding absolutely and in general. The motives of action are either the strongest and most durable instincts, or, in case of high culture, conventional agreement of that which benefits society. In the one as well as in the other case, when the duty is neglected, the appeal is not made to something absolutely objective and binding, but either to the highest instinct (and to this every individual has the right to answer with a _Quod nego_), or to agreement and custom; and as to this, every individual has the right to make his reformatory or revolutionary attempt at change--of course only upon the condition that his attempt is successful, and that it stands proof. Relatively it is easiest for ethical naturalism to establish a principle of _virtue_, inasmuch as we have to look upon virtue as the principle of individual perfection, and inasmuch as even naturalism, by means of the indestructible impulse of man to attain moral ideas, can postulate an ideal of human action. But on closer examination even the naturalistic idea of virtue vanishes under our hands. Virtue, as individual morality, is constituted of the factors of duty and of the highest good, which form the motives of virtuous action. Now a system of morality which, as we have seen, is entirely wanting in an objective solid principle of duty as the motive of action, and which likewise, as we shall see immediately, is wanting in an objectively established highest good as the end of action, cannot possibly {383} produce any other idea of virtue than an abstract formal one. In ethical naturalism, even this form is subject to change. For, according to this system, not only the motive and end but also the form of moral action depend on that which in every circle of society and at every time proves to be the most successful form. It is the proof of success or failure which gives this form a certain traditional authority and a relative solidity--but only a relative one, and only until it is displaced by a still more successful form.