The second set contains, a treatise on Things Similar, in three books, addressed to Aristocles; an essay on Definitions, in seven books, addressed to Metrodorus. The third set contains, a treatise, in seven books, on the Incorrect Objections made to Definitions, addressed to Laodamas; two books of Probable Arguments bearing on Definitions, addressed to Dioscorides; two books on Species and Genus, addressed to Gorgippides; one book on Divisions; two books on Contraries, addressed to Dionysius; a book of Probable Arguments relating to Divisions, and Genera, and Species; a book on Contraries. The fourth set contains, a treatise, in seven books, on Etymologies, addressed to Diocles; another, in four books, on the same subject, addressed to the same person. The fifth set contains, a treatise in two books, on Proverbs, addressed to Zenodotus; an essay on Poems, addressed to Philomathes; an essay, on How one Ought to Listen to Poems, in two books; an essay, in reply to Critics, addressed to Diodorus. The next division refers to Ethics, looked at in a general point of view, and to the different systems arising out of them, and to the Virtues. The first set contains, an essay against Pictures, addressed to Timonax; an essay on the Manner in which we express ourselves about, and form our Conceptions of, each separate thing; two books of Thoughts, addressed to Laodamas; an essay, in three books, on Conception, addressed to Pythonax; an essay, that the Wise Man is not Guided by Opinion; an essay, in five books, on Comprehension, and Knowledge, and Ignorance; a treatise on Reason, in two books; a treatise on the Employment of Reason, addressed to Leptines. The second set contains, a treatise, that the Ancient Philosophers approved of Logic, with Proofs to support the Arguments, in two books, addressed to Zeno; a treatise on Dialectics, in four books, addressed to Aristocreon; an answer to the Objections urged against Dialectics, in three books; an essay on Rhetoric, in four books, addressed to Dioscorides. The third set contains, a treatise on Habit, in three books, addressed to Cleon; a treatise on Art and Want of Art, in four books, addressed to Aristocreon; a treatise, in four books, on the Difference between the Virtues, addressed to Diodorus; a treatise, to show that all the Virtues are Equal; a treatise on the Virtues, in two books, addressed to Pollis. The next division refers to Ethics, as relating to Good and Evil. The first set contains, a treatise in ten books, on the Honourable, and on Pleasure, addressed to Aristocreon; a demonstration, that Pleasure is not the Chief Good of Man, in four books; a demonstration that Pleasure is not a Good at all, in four books; a treatise on what is said by …[106] BOOK VIII. LIFE OF PYTHAGORAS.