(Thomas Jefferson, 1743 - 1826.)From "Report on the Commissioners for the University of Virginia", quoted in The Portable Thomas Jefferson.
This doctrine ['that the condition of man cannot be ameliorated, that what has been must ever be, and that to secure ourselves where we are we must tread with awful reverence in the footsteps of our fathers'] is the genuine fruit of the alliance between Church and State, the tenants of which finding themselves but too well in their present condition, oppose all advances which might unmask their usurpations and monopolies of honors, wealth and power, and fear every change as endangering the comforts they now hold."
I paused before including Jefferson here: though certainly one of history's more commendable figures and notable for rejecting orthodoxy, I don't know much of a 'freethinker' he was. It seems he's worthy of honorary membership at the very least. He's one of my two favorite founding fathers, the other being Benjamin Franklin.