Read the excerpt from The Republic by Plato.

And if so, we must infer that all things are produced more plentifully and easily and of a better quality when one man does one thing which is natural to him and does it at the right time, and leaves other things.

Undoubtedly.

Then more than four citizens will be required; for the husbandman will not make his own plough or mattock, or other implements of agriculture, if they are to be good for anything. Neither will the builder make his tools—and he too needs many; and in like manner the weaver and shoemaker.

True.

Then carpenters, and smiths, and many other artisans, will be sharers in our little State, which is already beginning to grow?

True.

How does the speaker support the validity of his claim about how a society develops?

He shares his ideas for establishing a viable standard of living.
He describes the services that a given society would need.
He converses with someone who agrees with him.
He asserts that the community will expand.