Theism's Reasonableness and the Foundation of Human Rights

Robby George recommmends Grisez's in God? A Philosophical Preface to Faith for those interested in studying a compelling argument for the reasonableness of belief in God. 

In light of Brian Tamanaha August 21 post on Balkinization and in light of the comment made by Charles to a post on Steve Bainbridge's blog, I'll further clarify what I said in an ealier post, arguing that theists have a sturdier foundation for human rights than a-theists.

Is there a strong rational basis for human rights?  If so, what is it?

I agree with Brian T. that atheistic and materialistic foundations for human rights are tenuous.  How can there be a rational basis for inherent human dignity in an irrational universe?  There can't!

But, as Brian recognizes, there is a rational basis for inherent human dignity (which is the basis for universal human rights) if we were created by a certain type of God.  But, here is the stumbling block for Brian.  God's existence has not been proven.  From this he concludes, if I understand him correctly, that the theist's foundation for human rights is equally tenuous.  But, I think he requires too high a burden of proof - "a beyond a shadow of a doubt standard" - for God's existence.

If belief in God is reasonable, then theism (even by Brian's own logic, I think?) supplies a rational basis for human rights where atheism does not.  But, what if it is more reasonable (perhaps substantially more reasonable) to affirm God's existence than to deny it?  See Grisez.  Then it seems to me that the theist's foundation for human rights is sturdier still.

Now to Brian T's question of why does it matter?  Why do theists (like us at MOJ) risk alienating good, moral, human rights desiring atheists by insisting that theism provides a sturdier foundation for human dignity and rights than atheistic foundations?  First, we don't (or I don't) want to alienate any person of good will, theist or atheist.  We (I) desire and welcome fellow travelers from all walks of life and with all belief systems.  But, we (or at least I) do not think that a tenuous non-theistic (closed to special revelation and closed to general revelation - natural law) basis for human rights can protect the dignity of persons long term in the face of all the evil, selfishness, and unbridled desire for power and control in the world.  History has shown that even the sturdier (reasonable) theistic foundation has a hard time taming our disordered desire to treat other human beings as objects for our use and gratification.  An a-theistic foundation will have, I concluded, an even harder time and will ultimately fail because it cannot give a strong account of why a particular type of matter (the material that makes up a human being) ought to be respected in a solely materialistic universe.