In condemning animal sacrifice, he declares that “it is by means of an exalted and purified intellect alone that we can approximate to the Supreme Being, to whom nothing material should be offered.” He distinguishes four degrees of virtue, the lowest being that of the man who attempts to moderate his passions; the highest, the life of pure reason, by which man becomes one with the Supreme Existence. In the third book, maintaining that other animals are endowed with high degrees of reasoning and of mental faculties, and, in some measure, even with moral perception, Porphyry proceeds logically to insist that they are, _therefore_, the proper objects of Justice:-- “By these arguments, and others which I shall afterwards adduce in recording the opinions of the old peoples, it is demonstrated that [many species of] the lower animals are rational. In very many, reason is imperfect indeed--of which, nevertheless, they are by no means destitute. Since then justice is due to rational beings, as our opponents allow, how is it possible to evade the admission also that we are bound to act justly towards the races of beings below us? We do not extend the obligations of justice to plants, because there appears in them no indication of reason; although, even in the case of these, while we eat the fruits we do not, with the fruits, cut away the trunks. We use corn and leguminous vegetables when they have fallen on the earth and are dead. But no one uses for food the flesh of dead animals, unless they have been killed by violence, so that there is in these things a radical injustice. As Plutarch says, it does not follow, because we are in need of many things, that we should therefore act unjustly towards _all beings_. Inanimate things we are allowed to injure to a certain extent, to procure the necessary means of existence--if to take anything from plants while they are growing can be said to be an injury--but to destroy living and conscious beings merely for luxury and pleasure is truly barbarous and unjust. And to refrain from killing them neither diminishes our sustenance nor hinders our living happily. If indeed the destruction of other animals and the eating of flesh were as requisite as air and water, plants and fruits, then there could be no injustice, as they would be necessary to our nature.” Porphyry, it is scarcely necessary to remark, by these arguments proves himself to have been, in moral as well as mental perception, as far ahead of the average thinkers of the present day as he was of his own times. He justly maintains that