Sociological fact - empirical evidence.
Prove both.
Don't forget to include ALL societies. And what empirical evidence are you referring to? Said evidence must exist on its own free from human influence.
Gather 10 (or 100 or 1000) people, equal before the law and sane, and ask them these three questions:
1. Do you agree to observe our right to life in order to preserve your own?
2. Do you agree to observe our right to expression in order to preserve your own?
3. Do you agree to observe our right to self defense in order to preserve your own?
Same results, every iteration.
It doesn't matter where or even when one goes, all participants answer yes. These agreements are part of being human, inalienable. The drive is survival, individual, group and species. One's own answer of 'yes' is what makes the rights self evident.
The Enlightenment is about this concept replacing law by autocrat. This is the idea that spawns our ability to rule ourselves, as a nation and beyond. No longer would kings or theocrats decide our rights. We came to understand our rights as something not granted by man but nature - sociologically natural, universal agreements. Keep in mind, inalienable (not separable from mankind) does not mean inviolable. Individuals and authorities violate rights, but that does not make the right itself, the social agreement, go away.
Then, aware of the scientific foundation of a system of government to be controlled by the people, we have the American and French Revolutions.
Now, one can call the concepts of The Enlightenment, which lead to the Revolutions and modern Western World, an illusion or one can attempt to grasp them. If it's truly beyond one's grasp, of course it will always appear to be an elaborate trick.