" Rather than there being two distinct and unambiguous categories of
constrained and unconstrained (or tragic and utopian) visions of human
nature, I think there is just one vision with a sliding scale. Let’s call this the
Realistic Vision. If you believe that human nature is partly constrained in
all respects—morally, physically, and intellectually—then you hold a
Realistic Vision of human nature. "

― Michael Shermer , Brain, Belief, and Politics (Cato Unbound Book 92011)