Varro having followed the sect of the old Academy, in preference to all others, proceeded to refute the principles of the sects he had enumerated. He cleared the way, by dismissing, as unworthy the name of philosophical, all those sects whose differences did not turn on what is the supreme final good; for there is no use in philosophizing, unless it be to make us happy, and that which makes us happy is the final good. But those who dispute, for example, whether a wise man should follow virtue, tranquillity, &c. partly for the sake of others, or solely for his own, do not dispute concerning what is the final good, but whether that good should be shared. In like manner, the Cynic does not dispute with regard to the supreme good, but in what dress or habit he who follows the supreme good should be clad. So also as to the controversy concerning the uncertainty of knowledge. The number of sects were thus reduced to the twelve with which our author set out, and in which the whole question relates to what is the final good. From these, however, he abstracted the sects which place the final good in pleasure, rest, or the union of both—not that he altogether disdained these, but he thought they might be included in soundness of body and mind, or what he called the _prima Naturæ_. There are thus only three questions which merit full discussion. Whether these _prima Naturæ_ should be desired for the sake of virtue, or virtue for their sake, or if they and virtue also should be desired for their own sake. Now, since in philosophy we seek the supreme felicity of man, we must inquire what man is. His nature is compounded of soul and body. Hence the _summum bonum_ necessarily consists in the _prima Naturæ_ or perfect soundness of mind and body. These, therefore, must be sought on their own account; and under them may be included virtue, which is part of soundness of mind, being the great director and prime former of the felicity of life. Such were the doctrines of the old Academy, which Varro was also introduced as supporting in Cicero’s _Academica_.—“I have comprehended,” says that illustrious orator and philosopher, in a letter to Atticus, “the whole Academic system in four books, instead of two, in the course of which Varro is made to defend the doctrines of Antiochus(78). I have put into his mouth all the arguments which were so accurately collected by Antiochus against the opinion of those who contend that there is no certainty to be attained in human knowledge. These I have answered myself. But the part assigned to Varro in the debate is so good, that I do not think the cause which I support appears the better.”