In their previous book, Good God, David Baggett and Jerry Walls defended their theory of theistic ethics. Their theory grounds rightness in Divine commands and goodness in the Divine nature. In this second book, God and Cosmos, they aim to address competing secular ethical theories and show that they ultimately fail to provide an adequate account of the full range of moral phenomena in need of explanation. Instead, God and cosmos together best explain the moral phenomena (hence the title). Their methodology is to begin with various moral data, and then look at the explanations to see which best explains the various data. In short, they advance a cumulative abductive moral argument for God. In doing so, they assume moral realism, the view that objective morality exists. Whether moral realism is true will be addressed in another book to be published. God and Cosmos is rich in philosophy and many philosophical terms; in my summary, I will try to simplify it to be more accessible to the lay reader and highlight the main points.

Chapter 1: Alone in the Cosmos

Naturalism or materialism is the idea that the physical world exhausts reality. This view is held by many intellectuals. In this chapter, Baggett and Walls discuss naturalism and its history. They start a historical sketch all the way from the ancient philosopher Thales. Their brief sketch is meant to make three points.

The first point is what they call the deflationary fallacy. This fallacy is when one attempts to co-opt and appropriate a thinker (or insight) to the cause of one's worldview, despite compelling counter evidence. For example, some might cast the stoic philosophers as allies of naturalism. But this is difficult because their ethical thought was bound up in their theology as seen in many of their writings.

The second point is to highlight the diversity among secular thinkers. While Baggett and Walls generally use words like "atheistic," "secular," and "naturalistic" interchangeably, they note that there is a need to disambiguate at certain points. For example, an ethical realist who believes that there is no God may believe that moral facts are not reducible to natural facts. He is an atheist and secularist, but not a naturalist. This is an example of the diversity among secular thinkers. One significant set of atheists, who stand in the tradition of Friedrich Nietzsche, thinks that the death of God results in having no objective morality. The result is moral nihilism where there is no God and no objective morality. Another significant set of atheists think instead that without God, nothing much changes at all. On such a view, objective morality still exists. They however disagree upon which secular ethical theory is correct. Various secular theories need to be addressed differently. In this book, Baggett and Walls aim to address a range of different theories which affirm objective morality (and, again, will address those who deny objective morality in a later book).

The third point they wish to bring out is a third option beyond theism and naturalism. Their salient example is Thomas Nagel's account. Nagel thinks that naturalism is bound up with problems, yet he remains an atheist, resisting theism, by offering another alternative. In his book, Mind and Cosmos, Nagel argues that various features of the human condition - value, meaning, cognition, consciousness, agency - are beyond the ability of naturalism to account for. In finding an adequate explanation of value, Nagel divides the question into the constitutive issue concerning what value is all about and the historical question of how it could come about that we could recognize objective value and be motivated by it. Nagel opts for a nonintentional teleological (purposive) explanation. He writes that "these things may be determined not merely by value-free chemistry and physics but also by something else, namely a cosmic predisposition to the formation of life, consciousness, and the value that is inseparable from them." So Nagel thinks objective morality exists, yet naturalism cannot ground it, and yet he resists resorting to theistic foundations.

Nagel's recurring theme is also that the mind must be central to the story of reality, something that somehow guided the process form the start. However, Nagel is skeptical about theism for a few reasons. First, Nagel rejects theism because it does not seem to be a live option for him. He says while others may find it so, he has not been blessed with the sensus divinitatis (a sense of the Divine). Second, in finding an adequate explanation, he is committed to antireductionism and that certain things cannot be explained as merely accidental. The most important is "the ideal of discovering a single natural order that unified everything on the basis of a set of common elements and principles." Nagel thinks that accepting the Divine mind as the stopping point leaves the explanation incomplete. Theism on his view "amounts to the hypothesis that the highest-order explanation of how things hang together is of a certain type, namely intentional or purposive, without having anything more to say about how that intention operates, except what is found in the results to be explained." He further thinks theism and Cartesian dualism (the view that there exists a non-physical mind and physical body) fail to achieve a single natural order. For example, by appealing to miracles, one attempts to explain features of the world by appealing beyond the world. Hence he thinks that theism pushes the quest for intelligibility outside the world and fails to explain intelligibility from within the world. The only kind of theism that Nagel may accept is a non-interventionist one, where God created the world in such a way that it was henceforth self-sustaining and self-regulating.

Baggett and Walls offer a few replies. First, the fact that Nagel himself does not personally have a sense of the Divine is no evidence against theism. There is still the question of whether the arguments for theism are good ones. Second, Baggett and Walls argue that theism can meet Nagel's aesthetic bias in favor of an integrated worldview. They note that C. S. Lewis himself seemed to have anticipated such an objection, where people find miracles intolerable. The reason why they find it intolerable is because "they start by taking Nature to be the whole of reality. And they are sure that all reality must be interrelated and consistent." Lewis agrees with the aesthetic constraint for an integrated worldview but points out that the problem is taking nature to be the whole of reality. If God is real, then miracles still fulfill the aesthetic constraint. Lewis also addresses the concern that miracles are irregularities or arbitrary interventions. He says that if miracles have occurred, it is because they are the very thing this universal story is about; it is where the plot turns. Atoms, time, and space are not the main plot of the story. So miracles are not arbitrary or ad hoc interruptions. Lastly, Lewis also argued that if naturalism is true, we have no reason to trust our convictions that nature is uniform. But if theism is true, then it is plausible that our convictions are generally reliable, yet it also entails that miracles are plausible and are part of our world alongside the uniformity of majority of events. So theism can meet Nagel’s aesthetic constraint for an integrated worldview, and Nagel’s rejection of it is premature.