The Grote Difficulty

This is the way that, I'm thinking, that the Grote (a.k.a. 'Sachs') difficulty needs to be handled. Let me know what you think.

I noticed the other day that the bulk of Plato's argument about the virtue of justice in Book IV is aimed at establishing that the word 'just' as applied to a person with a well-ordered soul, and as applied to the ideal city, is used univocally. In fact, the arguments that the soul has three parts are introduced explicitly for this purpose: "a just man won't differ at all from a just city in respect to the form of justice" (435b). And Plato takes the point to be clinched by 442a: "Is the justice in us at all indistinct? Does it seem to be something different from what we found in the city?--It doesn't seem so to me". And then immediately following this is the appeal to 'ordinary cases', the inductive argument, which we've looked at already, that a just person won't embezzle, steal, break an oath, etc. (442e ff)--which confirms that Plato took the equivalence of i-justice and o-justice to follow from the univocity of 'just' as applied to an individual with i-justice and the ideal city. So consider the following argument.

Call the following the Univocity Thesis:

1. The justice of an individual with a well-ordered soul is the same sort of thing as the justice of an ideal city.

Now consider the following principle, which I shall call the Principle of Reflection:

2. The citizens of an ideal city resemble the city.

(The Principle of Reflection is the basis for the analogy between city and individual in the first place. Intuitively, it is the idea that citizens of a sort of city are 'suited' to live in that sort of city, and they become so suited by resembling the city of which they are a part.)

Then add also:

3. In an ideal city, acts of ordinary injustice will be forbidden.

We need as well:

4. The citizens of an ideal city are lawful.

Thus:

5. The citizens of an ideal city will not perform acts of ordinary injustice.

And then, by Univocity:

6. A person with i-justice will not perform acts of ordinary injustice.

The argument, in brief, is that i-justice may be understood as what suits someone to live in an ideal city. Because ordinary injustice is unlawful in such a city, i-justice suits or disposes someone to live without committing acts of ordinary injustice (or something like that).