Above all, he exclaims, we must not fail to notice what effect this doctrine has on the minds of those whom they have persuaded to despise the world and all that it contains. Of the two chief methods for attaining the supreme good, one has sensual pleasure for its end, the other virtue, the effort after which begins and ends with God. Epicurus, by his denial of providence, leaves us no choice but to pursue the former. But this doctrine [Gnosticism], involving as it does a still more insolent denial of divine order and human law, laughs to scorn what has always been the accepted ideal of conduct, and, in its rage against beauty, abolishes temperance and justice—the justice that is associated with natural feeling and perpetuated by discipline and reason—along with every other ennobling virtue. So, in the absence of true morality, they are given over to pleasure and utility and selfish isolation from other men—unless, indeed, their nature is better than their principles. They have an ideal that nothing here below can satisfy, and so they put off the effort for its attainment to a future life, whereas they should begin at once, and prove that they are of divine race by fulfilling the duties of their present state. For virtue is the condition of every higher aspiration, and only to those who disdain sensual enjoyment is it given to understand the divine. How far our opponents are from realising this is proved by their total neglect of ethical science. They neither know what virtue is, nor how many virtues there are, nor what ancient philosophy has to teach us on the subject, nor what are the methods of moral training, nor how the soul is to be tended and cleansed. They tell us to look to God; but merely saying this is useless unless they can tell us what the manner of the looking is to be. For it might be asked, what is to prevent us from looking to God, while at the same time freely indulging our sensual appetites and angry passions. Virtue perfected, enlightened, and rooted in the soul, will reveal God to us, but without it he will remain an empty name.[521] Even M. Vacherot, with all his anxiety to discover an Oriental origin for Neo-Platonism, cannot help seeing that this attack on the Gnostics was inspired by an indignant reaction of Greek philosophy against the inroads of Oriental superstition, and that the same character belongs more or less to the whole system of its author. But, so far as we are aware, Kirchner is the only critic who has fully worked out this idea, and exhibited the philosophy of Plotinus in its true character as a part of the great classical revival, which after producing the literature of the second century reached its consummation in a return to the idealism of Plato and Aristotle.[522]