As virtue was itself the end, it was of course choiceworthy in and for itself, apart from hope or fear with regard to its consequences. Moreover, as being the highest good, it could admit of no increase from the addition of things indifferent. It did not even admit of increase from the prolongation of its own existence, for the question was not one of quantity, but of quality. Virtue for an eternity was no more virtue, and therefore no more good, than virtue for a moment. Even so one circle was no more round than another, whatever you might choose to make its diameter, nor would it detract from the perfection of a circle if it were to be obliterated immediately in the same dust in which it had been drawn. To say that the good of men lay in virtue was another way of saying that it lay in reason, since virtue was the perfection of reason. As reason was the only thing whereby Nature had distinguished man from other creatures, to live the rational life was to follow Nature. Nature was at once the law of God and the law for man. For by the nature of anything was meant, not that which we actually find it to be, but that which in the eternal fitness of things it was obviously intended to become. To be happy then was to be virtuous, to be virtuous was to be rational, to be rational was to follow Nature, and to follow Nature was to obey God. Virtue imparted to life that even flow in which Zeno declared happiness to consist. This was attained when one's own genius was in harmony with the will that disposed of all things.