Of the Platonic dialogues there are two most general types, the one adapted for instruction and the other for inquiry. And the former is further divided into two types, the theoretical and the practical. And of these the theoretical is divided into the physical and logical, and the practical into the ethical and political. The dialogue of inquiry also has two main divisions, the one of which aims at training the mind and the other at victory in controversy. Again, the part which aims at training the mind has two subdivisions, the one akin to the midwife’s art, the other merely tentative. And that suited to controversy is also subdivided into one part which raises critical objections, and another which is subversive of the main position. I am not unaware that there are other ways in which certain writers classify the dialogues. For some dialogues they call dramatic, others narrative, and others again a mixture of the two. But the terms they employ in their classification of the dialogues are better suited to the stage than to philosophy. Physics is represented by the Timaeus, logic by the Statesman, Cratylus, Parmenides and. Sophist, ethics by the Apology, Crito, Phaedo, Phaedrus and Symposium, as well as by the Menexenus, Clitophon, the Epistles, Phalebus, Hipparchus and the Rivals, and lastly polities by the Republic, the Laws, Minos, Epinomis, and the dialogue concerning Atlantis.“ To the class of mental obstetrics belong the two Alcibiades, Theages, Lysis and Laches, while the Euthyphro, Meno, Io, Charmides and Theaetetus illustrate the tentative method. In the Protagoras is seen the method of critical objections; in the