This is a book about how Darwin's theory of evolution affects our view of religion and God, meaning of life and morality.
Evolutionary theory answers one of the most profound and fundamental questions human beings have ever asked themselves, a question that has plagued reflective minds for as long as reflective minds have existed in the universe: why are we here? The answer is simple: we are here because we have evolved from other species.
The concept of God has been among the most influential concepts in the history of the human species. The problem is, though, that trying to pin down a definition of God is a little like trying to nail jelly to a tree.
how did we and the other animals come to exist? In the early twenty-first century, there is really only one scientific answer to this question: we evolved. In popular culture, though, there is another contender. This is the position known as creationism. Creationists reject evolutionary theory as a huge mistake or even a Great Lie, invented (perhaps by the Devil) to lure people away from God and spread atheism.
Part of the book tries to establish the fact that Evolution really happened. Some evidence is provided: Fossil record, DNA, vestigial organs, etc.
The image-of-God thesis is the idea that we and we alone were created in the image of God and have an immortal soul, and that this is a fundamental difference between all humans and all other animals that justifies a fundamental difference in how we treat all humans v. all other animals. The rationality thesis is the idea that we and we alone possess rationality – the spark of reason – and that this is the difference that justifies privileging members of our species above all others.
Evolutionary theory undermines both these theses.
Reciprocal altruism theory highlights the fact that, if you give to others even if they do not give to you, you’re liable to be exploited. Assuming you don’t want to be exploited, you might decide to reject moral precepts such as ‘turn the other cheek’ and ‘resist not evil’, and instead deny help to those who don’t reciprocate.
In the end, our decisions on whether something is right or wrong should be based on an assessment of real risks and benefits, not on half-baked ideas about naturalness v. unnaturalness. So our moral precepts are based on reasoned arguments and there's probably no objective morality decreed by some god or supernatural deity.