Rationality...

[fajrdrako]

Past and present religious atrocities have occurred not because we are evil, but because it is a fact of nature that the human species is, biologically, only partly rational. Evolution has meant that our prefrontal lobes are too small, our adrenal glands are too big, and our reproductive organs apparently designed by a committee; a recipe which, alone or in combination, is very certain to lead to some unhappiness and disorder. - Christopher Hitchens, God Is Not Great, p. 8.

Rephrased:

Funny little human brains. How do you get around in those things? - The Doctor, in Doctor Who, "The Doctor Dances" by Steven Moffat