This enormously valuable addition to the historiography of religious and moral thought is packed with sources and conclusions of significance far beyond England. Christians had written apologetic works since antiquity, but after 1580 England saw an explosion of writings targeting a supposed surge of atheists, a newly perceived threat whose very implausibility demands study. Following on the works of George Buckley and Don Cameron Allen, Sheppard examines anti-atheism, not to get at atheism, but because the evolution of the genre over the long seventeenth century exposes how Christianity transitioned from the earlier image of the default atheist as intellectually weak—the “fool” of Psalm 14 who “said in his heart ‘there is no God’”—to the later image of the intelligent, articulate atheist philosopher.

Sheppard’s opening section reviews how the atheism feared during the Reformation and before was less unbelief than “misbelief” (26), a category that covered non-Christian religions, heterodox Christian sects, and, the largest focus, a supposed surge of hypocrites who professed orthodox doctrines but did not live by them. In the common division of atheism into practical atheism—living as if there is no God—and speculative atheism—holding sincere radical beliefs—Sheppard demonstrates earlier anti-atheists’ overwhelming focus on practical atheism. Most sixteenth- and early seventeenth-century anti-atheist authors denied the possibility of logic ever supporting unbelief, characterizing the speculative atheist as one who tries to drown reason in false arguments to justify a sinful lifestyle. Even Epicurus, in this reading, merely wanted to live as a hedonist, and (as Lactantius had said) invented justifications to comfort himself. Materialism might be tenth on a Reformation list of causes of atheism, but sinful appetites were first, and the famous phenomenon of deathbed repentance seemed to prove that atheist arguments were mere efforts at self-delusion, tissue-paper thin in the face of sinners’ true knowledge of the obvious existence of God, and the price of their sinful ways.

In the later seventeenth century, “impossible” speculative atheism seemed to become abruptly real in the persons of Hobbes, Spinoza, the Providence-denying Deist Charles Blount, supposed followers of Machiavelli, and also in Rochester, whose intellectual activities and hedonist lifestyle merged practical and speculative atheism. The anti-atheist confutatio now reimagined its target, less as a fool than an intelligent hypocrite, proud and mocking, motivated by sin but armored in false arguments strong enough to be worth refuting. Even the stock villain character of hedonist Epicurus was refigured, when Pierre Gassendi and Walter Charleton (redeploying an apologetic technique that had been used outside England by humanists) framed Epicurus as intelligent but mistaken, with some errors but other ideas—even atomism—worthy of examination. Yet this new Epicurus was still, like Rochester, half hedonist, and when the Cambridge Platonists Henry More, John Smith, and Ralph Cudworth drafted anti-atheist works, they made some logical assaults on theses of Hobbes and others, but primarily argued that the Christian Platonist’s virtuous character was the antidote to atheism, since atheism was fundamentally irrational, a rebellion motived by sinful character, merely propped up by argument. Tales of the famous apostate Francesco Spiera further clarify atheism’s association with apostasy.

The final three chapters chronicle the further breakdown of the focus on practical atheism. Close to 1700, anti-atheists adopted new tactics, including a “hedonic” approach, imitating Pascal’s Wager by arguing that belief is a happier state than atheism. This tactic aimed to lure hedonists to the faith, but instead finally exploded the assumption that atheists chose to be atheists to seek pleasure. Sheppard’s endpoint in 1720 marks, not the end of anti-atheist literature, but the end of the confutatio and the associated idea that positive atheist arguments were of secondary importance compared to the sinful character of the practical atheist. The newly plausible rational atheist then became the object of new arguments, controversial at first, such as Pierre Bayle’s claim that there can be virtuous atheists, and Richard Mandeville’s declaration that the quiet unbeliever is less dangerous than the anti-atheist street-corner preacher, whose fearmongering disrupts the state’s attempts to manage sin using laws that turn private selfishness toward public good—using incentivizing laws to turn the atheist into a good citizen would have been ludicrous when the atheist was, by default, irrational. Beccaria appears on the horizon.