Socrates and Phaedrus depart.

There are two principal controversies which have been raised about the
Phaedrus; the first relates to the subject, the second to the date of the
Dialogue.

There seems to be a notion that the work of a great artist like Plato
cannot fail in unity, and that the unity of a dialogue requires a single
subject. But the conception of unity really applies in very different
degrees and ways to different kinds of art; to a statue, for example, far
more than to any kind of literary composition, and to some species of
literature far more than to others. Nor does the dialogue appear to be a
style of composition in which the requirement of unity is most stringent;
nor should the idea of unity derived from one sort of art be hastily
transferred to another. The double titles of several of the Platonic
Dialogues are a further proof that the severer rule was not observed by
Plato. The Republic is divided between the search after justice and the
construction of the ideal state; the Parmenides between the criticism of
the Platonic ideas and of the Eleatic one or being; the Gorgias between the
art of speaking and the nature of the good; the Sophist between the
detection of the Sophist and the correlation of ideas. The Theaetetus, the
Politicus, and the Philebus have also digressions which are but remotely
connected with the main subject.

Thus the comparison of Plato's other writings, as well as the reason of the
thing, lead us to the conclusion that we must not expect to find one idea
pervading a whole work, but one, two, or more, as the invention of the
writer may suggest, or his fancy wander. If each dialogue were confined to
the development of a single idea, this would appear on the face of the
dialogue, nor could any controversy be raised as to whether the Phaedrus