This is an ambitious book. Philipse not only seeks to present his case against religion, but to situate it within the larger contexts of the history of philosophy and the history of science. He builds his critique from the ground up, systematically exploring many objections to a point before moving from it to the next one, making his overall contention very rigorous.

The book is arranged in three parts, consisting of six, four, and five chapters respectively. Part I addresses the necessity of natural theology in order to be an intellectually responsible believer. The first chapter addresses the ‘priority’ of natural theology, and the second gives a brief history of it. There was far too much left out of this chapter for my taste, but the author was making a point, and so only referenced the history that was directly relevant to that point. The next subject addressed is the objection to natural theology made by Reformed theologians and, increasingly, Reformed philosophers, most notably Alvin Plantinga. Plantinga has argued against evidentialism for his entire career and countered that belief in God can be properly basic, not based on anything else but the immediate experience of him. Philipse summarizes the Reformed objection in chapter three and takes it down in chapter four by defending an internalist, foundationalist epistemology. Unfortunately, by basing his analysis on a particular epistemology like this, he severely limits himself and the applicability of his critique. Chapter five argues for the rationality of natural theology, and how the believer owes us a ‘grand strategy’ as to how to validate religious claims. This leads to what Philipse calls ‘The Tension’: the natural theologian wants to put his claims on the same level as science, employing similar methods of verification, but this would require making them falsifiable, i.e. having the potential to be overturned.

Part II finally allows the author to narrow his focus onto his main target: Richard Swinburne's apologia for Christian theism. This is because Philipse sees Swinburne's cumulative-case Bayesian defense as the most likely candidate to meet his objections. He first addresses the notions of metaphor and analogy, and how Christians use them to describe God, arguing that such attempts, even Swinburne's, end up with an empty concept. He then goes over the claim that God exists necessarily, looking at Swinburne's six definitions of necessity. Next, he asks whether bare theism, the mere belief that God exists and created the universe, can make any genuine predictions à la scientific methodology. He concludes part II by going over the ways theists try to shelter their worldview from the second horn of the Tension; that is, by making it unfalsifiable.

Part III looks at Swinburne's attempt to make a Bayesian probability assessment of God's existence. The next three chapters criticize, respectively, cosmological arguments, teleological arguments, and ‘other inductive arguments’ for the existence of God, such as the moral argument, or Swinburne's argument from consciousness. The final chapter goes over religious experiences and whether such experiences can be formulated into an argument for why the non-believer should consider them to be veridical. Unsurprisingly, Philipse does not find any of these avenues persuasive.

God in the Age of Science is very well-structured. The ordering of the chapters seeks to show that the theist must begin with natural theology, so it is not one approach among many that she can opt out of. Once this is established, he argues that the concept of God is empty, so the theist is not asserting anything in her claims. If we ignore this, theism has no predictive power, and so no Bayesian-type argument (such as Swinburne's) can be constructed. Ignoring this, if we do construct a Bayesian argument, atheism ends up being more probable than theism. Additionally, this book is heavily referenced, allowing the reader to follow-up on many of the numerous claims made; it also has an excellent bibliography and index.

The positives of this book, unfortunately, are at least partially mitigated by two points. First, despite the depth of analysis, the analyses are often directed at the wrong targets, which often amount to straw men. For example, Philipse's conception of what it means for a belief to be defeated, particularly in the context of Plantinga's discussion of the topic, is misleading, suggesting that if someone disagrees with you, and they seem just as sincere and as well-informed, that gives you a rebutting defeater for your belief (49). Yet Plantinga's whole epistemology (indeed, his whole career) revolves around the claim that this is not the case. Plantinga formulates his notion of defeaters in the context of his anti-evidentialism, according to which one can be warranted in believing something even in the face of well-informed individuals who disagree. This is demonstrated, for example, in the Purloined Letter case, where all the evidence points to someone's guilt in having stolen a letter, but the person clearly remembers walking alone in the mountains at the time, and has no memory of stealing the letter (Warranted Christian Belief [New York: OUP, 2000], 371–72). Even though everyone else would conclude, on the basis of the evidence, that the person is guilty, it would be irrational for this person to reject his own memory beliefs and agree with them.

Here is another example: in critiquing cosmological arguments Philipse addresses the claim that an actual infinite amount of discrete objects could not actually exist. Specifically, he refers to the thought experiment of (David) Hilbert's Hotel which suggests that if a hotel with an infinite number of rooms actually existed, and each room was occupied, people could enter the hotel (perhaps from the infinite restaurant across the street) to check-in, and the proprietor could move the occupants around to make room for the new guests. Philipse claims that the difficulties do not prove an actual infinite is ‘logically impossible’ (227), and our inability to make sense of Hilbert's Hotel is simply due to the fact that it would not be possible on earth because we lack an infinite amount of resources to construct such a hotel, rendering it ‘inconceivable’ for us. But of course, the claim is not that it is logically impossible but that it is metaphysically impossible; and, at any rate, Philipse offers us no reason to accept his account of why our intuitions on the subject are misleading; he simply states that it ‘has been refuted by many critics’ (226) and moves on. Examples could be multiplied.

Second, while exhibiting a hyper-skepticism of all things religious, Philipse displays some credulity towards those claims that bolster his general thesis. Twice in the first chapter he references Andrew Dickson White's A History of the Warfare of Science with Theology in Christendom, a work that is not widely accepted by science historians. Yet not only is he aware of its failings, he insists that it is, nonetheless, ‘a classic overview’ and ‘of great value’ (n.10, 8). Showing such selective skepticism and bias right out of the gate immediately places the reader in a skeptical stance towards Philipse's other claims.

In another example, he considers the size of the universe as discovered by modern science to be incompatible with the Judeo-Christian tradition (146). If God created the universe for our benefit, then he would have just created our solar system, not the vast expanses that we now know exist. But he just throws this claim out there, as if it were self-evident, ignoring fundamental issues involved. For example, the ancients and medievals believed the universe was larger than they could imagine, and for all practical purposes the earth was an infinitely small mathematical point within it. Thus the insignificance of the earth was the settled tradition in Christendom, not something only discovered by modern science. Nor does he address the very relevant claim made by physicist Roger Penrose that smaller universes consisting of just our solar system would be much more likely to come about by chance than a universe like ours where the low entropy condition is met (The Road to Reality [New York: Knopf, 2005], 762–65). In other words, the actual universe is much less plausibly explained by chance than a universe that Philipse suggests would constitute evidence for divine design. Nor does he address the more basic issue of why the size of the universe would have anything at all to do with whether God exists and loves human beings. And of course, the whole thing is premised on the misperception that the Judeo-Christian tradition conceives human beings as the most important thing God created, something very few Christian theologians – historically and today – would accept. Again, examples could be multiplied.

In a sense, these problems should not be too surprising. Philipse is not arguing for atheism or naturalism, he is arguing for scientism and a simplified form of it at that: he is taking the unreflective, knee-jerk reaction to religious claims, ‘informed’ by the biases and urban myths of contemporary culture, and trying to defend it in toto rather than showing how it harbors genuine insights albeit with some fallacious excesses. Thus, he claims that science has refuted the claim that there are necessary truths; but while providing copious footnotes for other points, he offers the reader no reference for this controversial claim, nor any context for the implications of accepting it (77–78). This is a common pattern: Philipse often presents such claims as settled and established with no hint that they are, at least, contested, if not outright rejected by philosophers.

None of this is meant to imply that this book has little value. Interspersed with these problems are genuine insights of great import. The misguided discussion on defeaters, for example, comes with the very astute observation that Plantinga defines them in an internalist sense, which seems at odds with his externalist epistemology. This is a valuable insight; and once again, examples could be multiplied. The problem is not that this work lacks such value, but that it is uneven. This is a direct result of his project: he is trying to put some philosophical meat on the unreflective bones of a spontaneous reaction against religious claims. One must sift through a lot of chaff to find the kernels of wheat, but they are there if one is willing to pay attention.