Just as a postscript to my last post, it's interesting (to me, although probably to very few other people) that John Locke, the father of political liberalism, bases his liberalism on the truth that God the Creator is sovereign Lord over his creatures. He doesn't put it quite like that, but in his argument against absolute monarchy, Locke makes the point that human beings are "all the Workmanship of one Omnipotent and infinitely wise Maker... they are his property, whose Workmanship they are, made to last during his, and not another's, pleasure". (2nd Treatise on Gov't, section 6). It being the 17th century, and Locke being an Englishman, the language of property comes to him quite naturally. His argument is that since everyone belongs to God alone (and not therefore to any other human being), no human being can have absolute or abitrary power over another. (Particularly, no human being can have power to take another's life: but the principle is then enlarged). To claim absolute power over another is to make free with God's property.
The great thing about reading political theory from the 17th century is that you get to see the USA being founded on such theory. Very rarely does a political theory get put into practice! But Locke's theory did in the USA (with a bit of Rousseau mixed in, but that can't be helped). That's why the American government is so limited, and so self-limiting in its system of checks and balances. It's also why the idea of being "one nation under God", although a relatively recent addition, is implicit from the very beginning of the US.
Question: in the absence of God, is there any good foundation for a system of civil liberties?