The second part of the dialogue, which takes us up to about the halfway point, revolves
around two key insights, which Socrates introduces and gets Ion to agree to.
The first of these is that judgment requires knowledge.
That is, to be able to judge excellence in a particular subject matter requires knowledge
of that subject matter.
So that the person who is able to accurately determine who is it, that this guy is an excellent
doctor, this one is a mediocre doctor, and this one is a very poor doctor, that person
who makes those judgments can only do so on the basis of some kind of knowledge about
medicine itself.
Only the person with that adequate knowledge is capable of rendering accurate judgments.
In the context of Plato’s overall thought, we can see that this would be connected with
his theory of forms, and a kind of intellectual knowledge that lies as the rational foundation
of practical judgment.
This particular claim of Plato’s is open to challenge, and we might find ourselves
later on building a case that Plato is in fact wrong about this.
But that’s the first insight from the second part of the Ion.
The second is that knowledge of the whole art is, requires and is in fact identical
to the ability to judge quality in the subject matter.
So, if someone is said to have perfect knowledge, or knowledge of the whole art, say, of medicine,
that person then has the ability to judge excellent from mediocre from poor medical doctors.
In fact, the complete knowledge is nothing other than the ability to make those judgments
correctly, consistently.
This takes us up about to the halfway point of the dialogue, and then the third part,
in which Socrates, in a longer passage, articulates his theory about what’s going on with poets
and their performers.
Poets and performers, he says, are divinely inspired.
They do not speak from knowledge of what they talk about; they are somehow communicating
some kind of inspiration that goes beyond the rational, from the gods, which they communicate
then to their audience through their works.
The fourth part of the dialogue consists in the examination of several specific arts:
arts of charioteering, of medicine, of fishing, and other arts.
What’s happening here is that Socrates is searching for the performer or the poet’s
specific area of expertise.
If we think of the first half of the dialogue as addressing and refuting Ion’s claim to
have perfect knowledge of all things, that the poet and the performer is simply an expert
in all human affairs, that plainly is not the case, the second half seems to be an examination
searching for, well, just what kind of knowledge is it that poets and their performers, their
rhapsodes, might possess.
‘What are you expert in, Ion?’
Socrates seems to be asking in this fourth part.
The final part of the dialogue, the fifth part, is, I think, Ion’s last stand, where
he says: it’s military strategy, it’s the speech and actions of generals, that’s
the specific area of expertise which I as a performer, and Homer as a poet, must have.
Socrates dispatches this, and that marks the ironic conclusion of the dialogue.
One of the major themes I think you should look for as you read through Ion is the rivalry
between poetry and philosophy as sources of moral education, as sources of knowledge about
human life and how to live it.
The real live question here is: Who is the person who is best fitted to instruct us about
how we should live our lives?
Is it the poet, like Homer or, for us, Shakespeare?
Or is it the philosopher?
And on what basis do each of these people make claims about the quality and the truth
of what they tell us?
So that’s my quick overview of the five parts of Plato’s Ion dialogue.
In other videos, I will take a look at the logical structure of some of the arguments
in the dialogue, and also do a walkthrough of the text of the dialogue, with more detailed commentary.
Thanks for watching today; goodbye.