As for the learning, as well as lofty ideas, of the author of the treatise _On Abstinence_, there has been a general consensus of opinion even from his theological opponents. Augustin, himself among the most learned of the Latin Fathers, styles him _doctissimus philosophorum_ (“the most learned of the philosophers”), and, again, _philosophus nobilis_ (“a noble philosopher”), “a man of no common mind” (_De Civit. Dei_); and elsewhere he calls him “the great philosopher of the heathen.” Even Eusebius, his immediate antagonist, concedes to him the titles of “the noble philosopher,” “the wonderful theologian,” “the great prophet of ineffable doctrines” (ὁ τῶν ἀποῤῥητων μύστης). Donaldson, endorsing the common admiration of the moderns, describes his learning and erudition as “stupendous.” Amongst modern testimonies to the merits of Porphyry’s treatise, _On Abstinence_, the sympathising remarks of Voltaire are worth transcribing:-- “It is well known that Pythagoras embraced this humane doctrine [of abstinence from flesh-eating] and carried it into Italy. His disciples followed it through a long period of time. The celebrated philosophers, Plotinus, Iamblichus, and Porphyry, recommended and practised it, although it is sufficiently rare to practice what one preaches. The work of Porphyry, written in the middle of our third century, and very well translated into our language by M. de Burigni, is much esteemed by the learned--but he has made no more converts amongst us than has the book of the physician Hecquet.[80] It is in vain that Porphyry alleges the example of the Buddhists and Persian Magi of the first class, who held in abhorrence the practice of engulfing the entrails of other beings in their own--he is followed at present only by the Fathers of La Trappe.[81] The treatise of Porphyry is addressed to one of his old disciples, named Firmus, who became a Christian, it is said, to recover his liberty to eat flesh and drink wine.