Since Charles Darwin published The Descent of Man, his second major book about evolution, in 1871, researchers have made many discoveries that flesh out Darwin’s little-known ideas about the evolution of morality. Recent papers in Free Inquiry by Ronald Lindsay and James Hughes have touched briefly on the evolution of morality, but there’s much more to this important story. In this article, I will review key steps in the evolution of morality during three phases of the evolution of life on Earth and discuss implications for organized religion and its relationship to morality.
Darwin knew that his theory of evolution by natural selection faced several daunting explanatory challenges to be understood and accepted by scientists and the public. For example, in On the Origin of Species, published in 1859, Darwin described a general process for the seemingly improbable evolution of “organs of extreme perfection,” such as the human eye, whereby simple forms of the evolving eye might provide a benefit to survival. Darwin knew of few intermediate forms to list in support of his explanation, but he was right; scientists have since discovered a series of steps representing the evolution of the eye in a variety of current species, from simple light-sensitive spots, to spots within cups, to cups partially closed to form a “pinhole camera” proto-eye, to eyes with very simple lenses, and so forth.
The story of the intuitively improbable evolution of human morality is analogous to the story of the evolution of the eye, in that science has subsequently discovered many intermediate steps that flesh out Darwin’s broad but conceptually correct view of the origins of morality. In The Descent of Man, Darwin provided a general description of how morality evolved, with the advantageous foundations of morality emerging in social animals, in particular among our primate ancestors. Darwin’s explanation—and subsequent scientific discoveries—show that morality is not a mysterious exception to evolutionary theory that required supernatural intervention to emerge, as claimed by proponents of “theistic evolution.” In contrast to such supernaturalism, a naturalistic view of the theory of evolution helps us to see the parallels and the high degree of continuity between our species and others.