NOT long ago, an American philosopher, John Searle, ruefully observed that his colleagues seldom bothered to discuss the existence—or otherwise—of God: “It is considered in slightly bad taste to even raise the question. Matters of religion are like matters of sexual preference: they are not to be discussed in public.”Diderot and Bertrand Russell, two famous earlier non-believers, would also have been puzzled by what has happened to God at the hands of the western intelligentsia. Unbelief is widespread, yet few can be bothered to argue for their unbelief. This is partly because religion is now commonly treated in western societies as a lifestyle choice, a matter of taste, not reason. Yet can religious faith, with its many political and social consequences, be neatly ring-fenced in this way? Religious toleration rightly requires that you must let your neighbour practise his religion without fear of persecution or reprisal. In the light of the West's awful history of religious warfare, if nothing else, that is a hard won and admirable principle. But there is also a prevalent attitude—call it religious correctness—with which genuine toleration is easily confused: a polite and well-meaning reluctance to engage believers in the sort of robust clash of ideas that might discomfit them.A telling recent example of this new correctness is provided by Stephen Jay Gould's “Rocks of Ages”. Mr Gould is a zoologist and geologist at Harvard—a practitioner, that is, of the two sciences that did the most to undermine traditional Christian belief. Mr Gould says that he is not a believer but that he has “great respect” for religion, and: “I believe, with all my heart, in a respectful, even loving concordat between...science and religion.” His book is full of respect for religion, but nowhere is there any hint of what makes it worthy of such veneration. Is religion among the boons or ills of mankind? Does it do more harm than good? These are proper questions. But Mr Gould avoids them. He has proved himself an eager controversialist in several scientific fields, but here he seems unable to submit religion to the same rigorous questioning that he has applied elsewhere in his work. Instead, it seems, he opts for the polite and caring attitude. Mr Gould calls his thesis the principle of non-overlapping magisteria. Science and religion operate, he says, in different but “equally vital” spheres, with no common ground. They ought to observe “respectful non-interference” in their dealings with one another. The alleged conflict between the two “exists only in people's minds and social practices”. Science tries to document and explain facts, whereas religion operates in “the realm of human purposes, meanings and values—subjects that the factual domain of science might illuminate, but can never resolve.”This intellectual apartheid is less coherent than it may seem. By contrasting the religious realm of values with the realm of facts, Mr Gould exposes himself to a dilemma. Do all facts lie outside the realm of religion, or only facts about the natural world? If the former, then each religion is simply a set of moral teachings and attitudes which one accepts or rejects as a matter of taste. If the latter, and there is a mysterious class of “supernatural” facts that are allegedly outside the realm of science, then the age-old wars of science and religion are bound to break out once more.The result of any attempt such as Mr Gould's to insulate religion from criticism is the evisceration of faith. Deprived of its right to assert facts, Christianity, for example, is reduced to the status of a fan club for the sayings of Jesus. Many atheists would be perfectly happy to join it.Mr Gould's “separate-but-equal” solution is hardly original. These arguments are old—and abiding—ones, as Peter Bowler reminds us in his history of earlier attempts to reconcile modern science and contemporary religion. Focusing on early 20th-century Britain, he describes in scholarly detail different strategies for harmonising faith and knowledge: the sought-after alliance between liberal theologians in the Church of England and religious-minded scientists, and the rather different efforts of science-minded writers such as Julian Huxley and George Bernard Shaw to foster a modern, non-Christian religion. All the while, as Mr Bowler also reminds us, the conservative faithful on the one side and the atheists on the other—rationalists such as H.G. Wells or Marxist socialists—resisted calls for reconciliation of any kind.Has anything changed? Perhaps more than appears. Despite its title, Daniel Harbour's “An Intelligent Person's Guide to Atheism” is not so much an explanation or history of unbelief as a powerful piece of advocacy for rejecting the religious attitude altogether. Mr Harbour does a strong job of defending atheism against some of the secondary charges that have been levelled against it—such as the complaint that atheistic political regimes have turned out to be worse than religious ones, or that atheists, if they follow through on what they believe, are bound to be amoral. But he also, and this is the core of his book, makes a positive case for the rational superiority of unbelief.Starting from the sound premise that we know much less than we would like to about all sorts of things, Mr Harbour, an Oxford University graduate in mathematics and philosophy and now a student of linguistics at MIT, argues that we ought to aim for a world view that is a “Spartan meritocracy” rather than a “Baroque monarchy”. A Spartan approach, in his sense, endorses as small a set of assumptions or theories as possible; and a world view that is meritocratic is one in which beliefs are maintained only if they stand up to criticism and the test of evidence.Judaism, Christianity and Islam are, by contrast, in his view, Baroque monarchies. Taken as beliefs, they are teeming nests of unwarranted assumptions that are not required to pass any tests of merit, but are maintained largely because they are found in scripture or accepted by tradition. Much of his reasoning will be familiar to the devotees of anti-clerical writers such as Voltaire or openly godless ones such as Russell, but the overall structure of his approach is new. As Mr Harbour has a great deal of ground to cover in a mere 143 pages, many of the arguments are compressed, and his style of writing is not polished. But, with its powerful and wide-ranging arguments against theism of all kinds, Mr Harbour's short book, nevertheless, makes what may be the most powerful case available to the widely held but strangely silent creed of atheism.