Certainty vs. uncertainty: “In which are we more likely to be deceived, and in which has rhetoric the greater power?”

I’ve taught Plato’s Phaedrus before, but in the past I have mostly focused on brief passages in which the characters discuss writing, which is really just a side issue.

The purpose of today is mostly just to accustom my “History and Future of the Book” students to oral classical culture, in the hopes they’ll get more out of their exposure to Plato’s Apology of Socrates (which is on the syllabus for Wednesday).

This time around I asked the students to look at a section that explores the broader connection between rhetoric and truth. Plato notes that rhetoric has little value when everyone already agrees. It matters greatly when people who look at the same things form different ideas about it in their minds.

Detail from Raphael’s fresco, “The School of Athens” (at the Vatican)

Soc. When any one speaks of iron and silver, is not the same thing present in the minds of all?
Phaedr. Certainly.
Soc. But when any one speaks of justice and goodness we part company and are at odds with one another and with ourselves?
Phaedr. Precisely.
Soc. Then in some things we agree, but not in others?
Phaedr. That is true.
Soc. In which are we more likely to be deceived, and in which has rhetoric the greater power?
Phaedr. Clearly, in the uncertain class.
Soc. Then the rhetorician ought to make a regular division, and acquire a distinct notion of both classes, as well of that in which the many err, as of that in which they do not err?
Phaedr. He who made such a distinction would have an excellent principle.
Soc. Yes; and in the next place he must have a keen eye for the observation of particulars in speaking, and not make a mistake about the class to which they are to be referred.
Phaedr. Certainly. –Plato, Phaedrus