You seem to omit that's possible that we have universal pricinciples that's superior to whatever culture. You can attain these principles via philosophy. Any individuals can rediscover the values of free speech, freedom of government arbitrary, freedoms of thoughts and actions by just reflexion itself.
One cannot disassociate philosophical principles with the culture and history that brought about it.
By claiming there's some Universal Principal that's superior is basically saying that you're own beliefs and culture (presumably the one and the same as the proported Universal Principle) is superior.
This isn't mathematics where there's some objective truth.
