In response to a discussion of unalienable rights over at Glenn Greenwald.
We of course are playing word games here, but I'll give it a shot. Our rights come from the consensus we created when we asserted that we had them. That we put them in our founding documents for easy reference adds to their value. If you doubt the power of consensus then I suggest you burn all the money in your wallet because it has no value save what has been assigned to it by the power of consensus.
You make a valid point about how the lack of ownership of our own bodies is evidence that we have rights that are currently being violated, but if you had no rights beyond what the government grants, then you would have no basis to complain!
When Jefferson wrote the declaration of independence, he did indeed invoke the diety and referred to it as the source of the rights asserted. But he also said, "we hold these truths to be self evident" meaning that he had no reason to think that anyone in his audience wouldn't know exactly what he was talking about.
He also used the phrase "goverments are institued by men". When you refer abstractly to "not having any rights except what are granted by government" then you are allowing 1 useful fiction to trump another useful fiction. Government is nothing more than a collection of people, many of whom are armed, who assert the right to control the behavior of others.
No wonder, when designing a system of government, the framers were very careful to design it in such a way that the ambitions of its participants are set against each other so that the power of law wouldn't become an instrument of abuse.
Opinions vary on how well they did, but it certainly highlights why its important to continue to assert our rights, even when we are among those who would sacrifice them for expedience or safety.