William Voegeli:
What sets the politicians of 2009 apart from the ones of 1787 is the pervasive modern denial that human nature is something we can understand and a basis on which we can found a political order.
The Americans who wrote and ratified the Constitution believed in certain truths about human nature. These included our fundamental equality, the securing of our inalienable rights as the government’s raison d’être, and the need to channel the natural selfishness that engenders factionalism through a constitutional mechanism that protects individual rights and promotes the public good.
The modern belief, instead, is that what matters is human history, not human nature, our evolution rather than our essence.