Plato, Laws 722b

ἀλλʼ οὐ τὰ βραχύτατα οὐδὲ τὰ μήκη τιμητέον—τὰ δʼ ἐν τοῖς νυνδὴ νόμοις ῥηθεῖσιν οὐ διπλῷ θάτερα τῶν ἑτέρων διάφορα μόνον εἰς ἀρετὴν τῆς χρείας, ἀλλʼ ὅπερ ἐρρήθη νυνδή, τὸ τῶν διττῶν ἰατρῶν γένος ὀρθότατα παρετέθη. πρὸς τοῦτο δὲ οὐδεὶς ἔοικε διανοηθῆναι πώποτε τῶν νομοθετῶν, ὡς ἐξὸν δυοῖν χρῆσθαι πρὸς τὰς νομοθεσίας, πειθοῖ καὶ βίᾳ, καθʼ ὅσον οἷόν τε ἐπὶ τὸν ἄπειρον παιδείας ὄχλον, τῷ ἑτέρῳ χρῶνται

but their excellence; and in the case of the laws mentioned just now, not only does the one form possess double the value of the other in respect of practical excellence, but the example of the two kinds of doctors, recently mentioned, presents a very exact analogy. But as regards this, it appears that no legislator has ever yet observed that, while it is in their power to make use in their law-making of two methods,—namely, persuasion and force,—in so far as that is feasible in dealing with the uncultured populace, they actually employ one method only: in their legislation they do not temper compulsion