The natural division of Ethics is into Individual Ethics and Social Ethics. It has sometimes been assumed that the whole duty of man could be summed up in Individual Ethics. However, it is not necessarily true that that which assists the best development of the individual serves society as a whole also. When the attention is directed so excessively to oneself, the general welfare is likely to be forgotten. On the other hand, a too great subjection of individual interests makes a man a mere parasite, robbing him of all self-dependence. When Ethics condemns the instinct of self-preservation, it condemns its own means. If the impulse to self-preservation, self-assertion, and self-development were evil, then our essential nature would be evil, and Ethics would be impossible. The right relation of the two principles is given in the principle of welfare. Mill's book "On Liberty" denies the ethical significance of self-development and forgets the individual's oneness with his kind, in declaring personal vices of no importance to the general welfare. That which Mill wished to defend was the freedom of the individual, the loss of which through the compulsion of society and the "moral police" he feared. But he might have accomplished this purpose without denying the ethical value of self-development. There is nothing that is a ground for greater solicitude than the mistake that public opinion and Ethics are one, and that a condition of things is no longer a subject for ethical condemnation when no outer power has the right to denounce it. The first question which presents itself in Individual Ethics is: How is the individual to educate himself to an ethical personality? Here the development and strengthening of the ethical principle as governing and determining the life of the individual is concerned. The problem is one with the determination of the chief virtue which includes all other ethical qualities. This virtue is justice, which includes in itself the two groups contained under Self-assertion and Self-sacrifice.[78]