The Nature of Rights and the Rights of Nature.
Like any thoughtful essay, this one doesn’t offer a simple answer to a complex question, but rather, it invites a reader to challenge his or her own assumptions. It’s surely done that for this reader. Thank you gentlemen!
A 'right' - whether it is thought of as a mere convention, or as a metaphysical entity - is an essentially *relational* concept. A right puts moral actors into a certain kind of relation. That relation is a *claim* by one person on the resources of another person (which can include corporate entities, not just individuals). It is a claim for a 2nd (and thence a 3rd) to commit resources either for the benefit of the claimant, and/or to forbear from taking certain actions which cause harm to the claimant.
A 'right' is a peculiar kind of entity, one which bears a strong affinity to natural language in humans, in that rights are both rooted in nature, as well as involve an ineliminable amount of human artifice.
But whether rights are natural or "merely" conventional, rights are relational, and therefore cannot be "absolute." It makes no moral sense whatever to be "granted rights" by a king (or anyone else), since the king can just as easily revoke the "right" at his whim. No given individual moral actor, no person is in a position to declaim the sphere of rights that another moral actor enjoys, any more than one individual person can claim to a have a private language. Rights, like language itself, have an essentially public significance, beyond the fiat of any given individual moral actor. The claim that "the Creator endowed us with rights," understood not metaphorically but literally, is nonsensical.