2. Ethics dealing with the common view and the sciences and virtues thence arising. First series : Against the Touching up of Paintings, addressed to Timonax, one book. How it is we name each Thing and form a Conception of it, one book. Of Conceptions, addressed to Laodamas, two books. Of Opinion or Assumption, addressed to Pythonax, three books. Proofs that the Wise Man will not hold Opinions," one book. Of Apprehension, of Knowledge and of Ignorance, 6 four books. Of Reason, two books. Of the Use of Reason, addressed to Leptines. Second series : That the Ancients rightly admitted Dialectic as well as Demonstration, addressed to Zeno, two books. Of Dialectic, addressed to Aristocreon, four books. Of the Objections urged against the Dialecticians, three books. Of Rhetoric, addressed to Dioscurides, four books. Third series : Of formed State, or Habit, of Mind, addressed to Cleon, three books. Of Art and the Inartistic, addressed to Aristocreon, four books. Of the Difference between the Virtues, addressed to Diodorus, four books.