The Republic by Plato Part 4 Page 21

would you say? there may also arise questions about any impositions and exactions of market and harbour dues which may be required, and in general about the regulations of markets, police, harbours, and the like.

But, oh heavens! shall we condescend to legislate on any of these particulars?

I think, he said, that there is no need to impose laws about them on good men; what regulations are necessary they will find out soon enough for themselves.

Yes, I said, my friend, if God will only preserve to them the laws which we have given them.

And without divine help, said Adeimantus, they will go on for ever making and mending their laws and their lives in the hope of attaining perfection.