This bookis a concise, deep, challenging, and wide-ranging critique of philosophical naturalism. In it, philosopher J.P. Moreland argues that there are several aspects of reality which naturalism is unable to account for, while theism can: consciousness, free will, rationality, morality, value, and a substantial human soul. The arguments are controversial and many will disagree, but I would urge anyone who has the time and inclination to read and think about this book, if you are wondering whether naturalism is the most rational worldview, or more rational than theism. If Moreland is right, and I think he is, theism has more explanatory power regarding many central aspects of human persons. I don't agree with everything in the book, of course, but the case is very well made.
Rather than summarizing the entire book, I will focus on the last chapter which is entitled "Naturalism, Objective Morality, Intrinsic Value and Human Persons." Moreland begins the chapter by noting 3 features of the moral order:
1. objective, intrinsic value and an objective moral law;
2. the reality of human moral action; and
3. intrinsic value and human rights.
His claim is that these features of moral reality fit very well within a theistic worldview. By contrast, some naturalist philosophers believe that naturalism yields defeaters for these aspects of moral reality. Moreland alludes to naturalists John Bishop and Michael Ruse as examples of such philosophers. (As a side note, other naturalists, such as Erik Wielenberg, would disagree. But Moreland's points count against a naturalist view which seeks to accomodate such non-natural properties within its ontology if he's right that these features have better metaphysical fit within a theistic framework.)
Moreland offers an argument that the following features are defeaters for a naturalistic worldview. To fully appreciate and evaluate his argument of course requires reading the chapter in the book, but I'll give a quick summary of his points.
1. The existence of objective moral value: If the universe starts with the Big Bang, and over its history we find the arrangement of microphysical entities into increasingly complex physical compounds, how does value arise? How can a naturalist, as a naturalist, embrace non-natural, objective, values?
2. The nature of the moral law: The moral order presents itself imperatively, that is, as something which commands action. The sense of guilt one feels for falling short of the moral law is best explained if a good God is the source or ultimate exemplification of that law. As Moreland puts it, "One cannot sense shame and guilt towards a Platonic form" (p. 147).
3. The instantiation of morally relevant value properties: Even if a naturalist allows for the existence of some Platonic realm of the Forms, the naturalist has no explanation for why these universals were and are instantiated in the physical universe.
4. The intersection of intrinsic value and human persons: How is it that human beings are able to do as morality requires, and that such obedience to the moral law also happens to contribute to human flourishing? Theism has an obvious answer to such questions related to human nature and the intentions of God, but it is not clear, and is far from obvious, how naturalism would account for this.
5. Knowledge of intrinsic value and the moral law: Given that such values are not empirically detectable and cannot stand in physical causal relations with the brain, how is it that we could know such things? Evolutionary explanations fall short because of what is selected for in evolutionary processes on naturalistic versions of evolutionary theory.
6. The nature of moral action: Here, I will simply quote Moreland, "...evolutionary naturalism would seem to predict a world of wantons. Since genuine moral agents understand moral duty and conflicts involving moral duty, wantons cannot be depicted as such. What is at issue is whether evolutionary naturalism has the intellectual resources to avoid implying a wanton world. In my view, evolutionary naturalism does not have those resources" (p. 153).
7. An adequate answer to the question, "Why should I be moral?": Both naturalists and theists can respond, "Because it is the moral thing to do." But beyond this, when thinking about the question outside of the moral point of view, the issue becomes why is it rational to adopt the moral point of view rather than an egoistic one? According to Moreland, this is a problem for the naturalist. But the theist can offer a variety of reasons to adopt the moral point of view--the moral law is true; it is an expression of the non-arbitrary character of a good, loving, wise, and just God; and we were designed to function properly when living a moral life.
The rest of the chapter includes a discussion of the value of human beings and rights, and I'll leave it to the interested reader to explore. The book is worth the price, and I highly recommend it for those inclined to do the work of reading and considering the arguments it contains.