The Peripateticians Ammonius and Ptolemy, who were the most learned of their contemporaries, especially Ammonius, whose erudition was unequalled, none of these philosophers wrote any important work; they limited themselves to writing poems, or festal orations, which have been preserved in spite of them. I doubt very much that they wished to be known by posterity merely by books so small (and unrepresentative), since they had neglected to acquaint us with their teachings in more significant works. Among those who have left written works, some have done no more than gather or transcribe what has been left to us from the ancient (philosophers); among these are Euclides, Democritus and Proclinus. Others limited themselves to recalling some details extracted from ancient histories, and they tried to compose books with the same materials as their predecessors, as did Annius, Medius, and Phebio; the latter one trying to make himself famous by style, rather than by thought. To these we might add Heliodorus, who has put in his writings nothing that had not been said by the ancients, without adding any philosophical explanation. But Plotinos and Gentilianus Amelius, have shown that they really made a profession of being writers, both by the great number of questions they treated, and by the originality of their doctrines. Plotinos explained the principles of Pythagoras and Plato more clearly than his predecessors; for neither Numenius, nor Cronius, nor Moderatus,[20] nor Thrasyllus,[21] come anywhere near the precision of Plotinos when they touch on the same topics. Amelius tried to follow in his footsteps, and adopted the greater part of his ideas; but differs from him in the verbosity of his demonstrations, and the diffusion of his style. The writings of these two men alone deserve special consideration; for what is the use of criticizing the works of imitators; had we not better study the authors whose works they copied, without any additions, either in essential points, or in argumentation, doing no more than choosing out the best? This has been our method of procedure in our controversy with Gentilianus Amelius's strictures on justice, in Plato's works; and in my examination of Plotinos's books on the Ideas.[22] So when our mutual friends Basil of Tyre, (Porphyry[23]), who has written much on the lines of Plotinos, having even preferred the teachings of Plotinos to my own (as he had been my pupil), undertook to demonstrate that Plotinos's views about the Ideas were better than my own, I have fully refuted his contentions, proving that he was wrong in changing his views on the subject.[24] Besides, I have criticized several opinions of Gentilianus Amelius and Plotinos, as for instance in the "Letter to Amelius" which is long enough to form a whole book. I wrote it to answer a letter sent me from Rome by Amelius, which was entitled "The Characteristics of the Philosophy of Plotinos."[25] I, however, limited myself to entitling my little work,