And the good thing is that they did; it didn't come from 5000 years of Chinese culture, nor 3500 years of Indus valley culture, nor various Central or South American cultures. It came from those "1000 years of grinding human misery" centered in Europe.
And the reason those cultures didn't produce a free society is because they had too much sexual license and not enough state censorship, right? (We'll ignore the free society of classical Athens arose out of a licentious atmosphere of open homosexuality and politically powerful prostitutes, as being inconvenient to your argument. We'll also ignore the fact that nobody has a clue as to what sort of society existed in the Indus Valley; if we ever decipher their writings someday we might figure it out.)