Natural Law

The Stoic philosophers are an under-rated bunch. Bertrand Russell offers the typical reaction, in his A History of Western Philosophy:

There is, in fact, an element of sour grapes in stoicism. We can't be happy, but we can be good. Let us therefore pretend that, so long as we are good, it doesn't matter being unhappy. This doctrine is heroic, and in a bad world, useful; but it is neither quite true nor, in a fundamental sense, quite important.

The most famous of the Stoic philosophers, of course, is the Roman emperor Marcus Aurelius. In his Meditations, he wrote of:

... a polity in which there is the same law for all, a polity administered with regard to equal rights and equal freedom of speech, and the idea of a kingly government which respects most of all the freedom of the governed ...

This was from the Big Guy himself, back around AD 170 to 180. While he clearly did not mold his Empire to fit this vision, educated society did pick up this notion of jus naturale - Natural Law. The early Church absorbed it from the upper classes, and it ultimately flowered in the Renaissance, and especially the Enlightenment.

Compare: a ... government which respects most of all the freedom of the governed ...

with: ... deriving their just powers from the consent of the governed.

Some "sour grapes". Somehow, I don't think that the old Emperor would be surprised at the fruits of his pen. After all, he wrote this in Meditations:

How ridiculous and unrealistic is the man who is astonished at anything that happens in life.