In one of Stamos’s most controversial chapters, he considers the role evolution plays in ethics. He considers ideas from John Alcock, Aristotle, Ruth Benedict, Jeremy Bentham, Charles Darwin, Richard Dawkins, Thomas Hobbes, David Hume, Immanuel Kant, John Locke, John Stuart Mill, G.E. Moore, Thomas Nagel, Plato, John Rawls, W.D. Ross, Michael Ruse, Albert Schweitzer, Peter Singer, Herbert Spencer, Paul Taylor, Robert Trivers, G.C. Williams, E.O. Wilson, and Peter Woolcock. Stamos’s approach is to contrast various thinkers against one another to discover ethical truths and whether or not evolution can provide any help.
He covers Social Darwinism, the naturalistic fallacy, natural rights, social constructionism, social and selfish instincts, psychological egoism, sociobiology, reciprocal altruism, noncognitivism, utilitarianism, virtue ethics, and deontology. He ultimately concludes that an absolute theory of ethics is arbitrary and biased; and to avoid these problems would require the principles of evolution to get its feet off the ground; and that any useful, comprehensive theory of ethics must be firmly planted in the realm of evolutionary biology.
One of Stamos’s weakest points is an oversimplification based on the “blind men and the elephant” parable to describe how virtue ethics, psychological egoism, deontology, utilitarianism, Rawls’ veil of ignorance, and environmental and feministic ethics are simply just parts of a larger normative ethics which has its grounding in evolution. Admittedly it is just a parable, but most of these theories are incompatible in a way that different parts of an elephant are not, and Stamos says little about how one would avoid the incompatibilities. On the other hand, he does end up rejecting ethical absolutism, which may allow him to say various otherwise incompatible ethical theories are all true within restricted domains. This move would be a major revision of standard views in normative ethics.
Stamos’ chapter on evolution and religion is arguably the weakest in the book. While in previous chapters Stamos is sometimes guilty of painting his opponents in broad strokes, his ideas are typically coherent and plausible. In this chapter, on the other hand, some of us believe that Stamos is less convincing. His principle weakness is to assume that “divine inspiration,” or the truthfulness of religion must compete with evolution's capability to explain it. He seems to assume that the explanation of religion provided by evolutionary psychology implies that one should believe in atheistic evolution.
As he puts it, “Atheistic evolution is simple (it is completely down to earth and involves nothing supernatural), it is objective (it is not what one wants to believe), it is internally and externally consistent with what is known in other sciences... it is fruitful... But is it testable?... atheistic evolution is testable. At the genetic level alone, one can conceive of observations that would refute it, such as, a string of sequences in DNA that would be ridiculous to explain by chance or by natural selection” (p. 200).
“Atheistic evolution” is arguably less simple than just “evolution,” with nothing new to predict or contribute. As for testability, his point is contestable. Using Ockham's Razor and the inference to the best explanation, both of which he uses to criticize others for beliefs that “don't respect science,” one could argue that “atheistic evolution” is at least as falsifiable as “evolution”; and therefore evolution, being the simpler theory, can be inferred as superior to “atheistic evolution.” Additionally, Stamos’s claim that “theistic evolution” isn't falsifiable and therefore “atheistic evolution” is better science is also questionable. If evolution is found to be false, theistic evolution is falsified, and hence if evolution is falsifiable so is “theistic evolution.”
In the final chapter of the book, “Evolution and the Meaning of Life,” Stamos discusses the meaning of life from an evolutionary standpoint. He examines the compatibility of evolutionary biology and existentialism in addition to trying to answer the questions of “whether evolution adds any meaning to life, takes away from it, or has no relevance” and “whether we have a basic need, evolved instinctual need, to find meaning of our lives” (p. 215). As in earlier chapters, Stamos takes the viewpoint of evolutionary biology. Arguably, evolution gives humans little choice but to keep playing the game of survival and reproduction. Following later Richard Dawkins, Stamos suggests that science does not rob the world of meaning, but rather fuels our sense of awe at its grandeur. In the most interesting argument of the chapter, Stamos follows Robert Nozick and argues that the meaning of life is relative to each individual and that one should strive to be connected to other people and things, and that humans can seek the meaning of life through the pursuit of knowledge or through personal relationships. The chapter ends with Stamos arguing that it does not really matter if the universe has a meaning or not, but that evolution has bestowed us with the ability to perform logic and appreciate the fallacy of division. Just because the universe as a whole does not have meaning, it does not follow that no individual person has a meaningful life. What is wrong with existentialism and the SSSM is that they both rely on false conceptions of human nature. Evolutionary thinking suggests that human nature is well described by “statistical norms,” and we are not utterly free as Sartre thought, nor do we start as a blank slate as one reading of SSSM asserts.