A fragment of a lost Platonic dialogue

[Author unknown; received from Rosalind Hursthouse, who got it from Montgomery Furth]

Is not the whole, Callicles, greater than the part?

Without doubt.

And the part is smaller than the whole?

Assuredly.

But if the part is smaller than the whole, then the whole is larger than the part?

So I believe.

And if the whole is greater than the part, then the part is smaller than the whole?

Certainly.

Is it as certain as that? Could you conceive a part which would contain the whole?

Never.

But you do conceive a whole which contains a part?

Surely.

And the whole, constituting the part, is greater than it?

Yes.

It follows that philosophers should be the rulers of the State.

How does that follow?

There can be no doubt. Let us begin again. The whole is greater than the part...