Evolution

Natural selection operates on the boundaries within which ethical systems can develop and it buffers humans against arbitrary indoctrination by capricious idealogies or programs of reinforcement that would work against the long-range survival of the human genotype.
		p. 91
P. H. Wolff	"The Biology of Morals from a Psychological Perspective" Morality as a Biological Phenomenon, G. S. Stent, ed. University of California Press, 1980
Cited in Michael Friedman, "Toward a Reconceptualization of Guilt," Contemporary Psychoanalysis 21(4), 1985 p. 511.