Smith discusses the common argument that atheists cannot be moral and so should not be legally tolerated.

George H. Smith was formerly Senior Research Fellow for the Institute for Humane Studies, a lecturer on American History for Cato Summer Seminars, and Executive Editor of Knowledge Products. Smith’s fourth and most recent book, The System of Liberty, was published by Cambridge University Press in 2013.

In his charming book Thinking Straight (Prometheus, 1977), the philosopher Antony Flew dubbed a common fallacy in reasoning the No‐​true‐​Scotsman Move. Flew wrote:

Imagine some Scottish chauvinist settled down on Sunday morning with this customary copy of The News of the World. He reads the story under the headline, ‘Sidcup Sex Maniac Strikes Again.’ Our reader is, as he confidently expected, agreeably shocked: ‘No Scot would do such a thing!’ Yet the very next Sunday he finds in that same favourite source a report of the even more scandalous ongoings of Mr. Angus MacSporran in Aberdeen. This clearly constitutes a counter example, which definitively falsifies the universal proposition originally put forward….Allowing that this is indeed such a counter example, he ought to withdraw; retreating perhaps to a rather weaker claim about most or some. But even an imaginary Scot is, like the rest of us, human; and we none of us always do what we ought to do. So what in fact he says is: ‘No true Scotsman would do such a thing.’

The No‐​true‐​Scotsman Move consists of making a universal statement about a certain class of people and then, when confronted with obvious counterexamples, redefining that class so that the original statement becomes true by definition. No Scotsman would commit sex crimes, so if a Scot appears to have done this, he could not have been a true Scotsman. If we wish to see contemporary examples of this devious tactic, we need only watch President Obama whenever he tells us how no Muslim could possibly commit the atrocities perpetrated by so‐​called radical Islamists. Therefore, according to Obama, any self‐​identified Muslim who commits terrorist acts cannot be a true Muslim at all. The hypothetical Scotsman in Flew’s example would have been very pleased with this bit of craziness in high places.

The No‐​true‐​Scotsman Move was popular for centuries among those Christian theologians who embraced the common distinction between speculative (or theoretical) atheists and practical atheists. The existence, indeed the very possibility, of speculative atheists was a topic of serious debate, especially among those philosophers who claimed that the idea of God is innate in every human being. This was the position taken by Edward Herbert (Lord Cherbury) in his 1624 book, De Veritate (On Truth). According to Herbert, every person is born with the idea of God (potentially if not actually), so true speculative atheists do not and cannot exist. As for those people who claim to be atheists, Herbert commented: “I am not deterred by the fact that irreligious men exist, and even some who appear to be atheists.” In fact, such people are not really atheists at all, because they merely reject a god who has been endowed by some believers with unworthy attributes. If these “atheists” were presented with a correct portrait of God, “they would pray that such a God might exist, if there were no such Being.”

If we still insist on the existence of real atheists, then Herbert reminded us that there are always a few “madmen and fools” around—those “men so stubborn and unreasonable that they were incapable of distinguishing truth from probability, possibility, and falsity.” Herbert was concerned only with “what all men of normal mind believe.” Thus, having posited the innate idea of God, Herbert dismissed counterexamples as products of abnormal minds.

This won’t wash, and John Locke knew it. In An Essay Concerning Human Understanding (1690), Locke launched a devastating attack on innate ideas generally and on Herbert’s theory specifically. Thereafter, with the theory of innate ideas in serious disrepair, the controversy over speculative atheists diminished somewhat, but the problem of practical atheism raged on.

Basically, a practical atheist was any person who acted so immorally, so contrary to the Christian moral code, as to disqualify himself as a true Christian, whatever his beliefs may have been. Such moral monsters are practical atheists, not authentic Christians. The category “practical atheist” was premised on the widespread belief that atheists are incapable of being moral persons. This belief was virtually axiomatic for many theologians, and it was a belief with immense practical implications. If atheists are necessarily immoral, if they are incapable of moral actions, then they cannot possess the civic virtues, such as a regard for justice, on which every society depends. Atheists (so this line of reasoning went) should therefore not be tolerated, for they threaten the essential fabric of every society. A society of atheists could not exist in any meaningful sense; without belief in God, a society would degenerate into the amoralism of the Hobbesian state of nature—a war of all against all in which social cooperation, based on mutual trust, is rendered impossible.

We should not suppose that the myth of the immoral atheist was propagated only by ignorant bigots. On the contrary, it was defended by some of the best minds of the seventeenth century. John Locke, for example, excluded atheists (and Catholics) from his arguments for religious toleration. As Locke wrote in A Letter Concerning Toleration (1689):

Those are not to be tolerated at all who deny the being of God. Promises, covenants, and oaths, which are the bonds of human society, can have no hold upon an atheist. The taking away of God, though but even in thought, dissolves all.

In this matter some Catholics tended to be more reasonable than Protestants. To understand the reason for this, we must understand the enormous influence of the doctrine of original sin on Christian thinking about the nature of man. In the theory of Augustine (353–430), all of man’s natural faculties, including his ability to reason, had been corrupted by original sin. This meant that without the grace of God man was incapable of desiring the good or even of knowing the good. This doctrine of total depravity was modified centuries later in the more rationalistic approach of Thomas Aquinas (1225–74). Aquinas maintained that although original sin had vitiated the natural desires of man, his ability to reason had been left largely unimpaired. Even sinful human beings could know the basic moral precepts of natural law through reason alone, without the aid of God or divine revelation. Thus even atheists are capable of actions that conform externally to essential moral rules, even if they lack the inward qualities that make their actions truly virtuous. As Aquinas wrote in his Summa Theologica: “Unbelief does not so wholly destroy natural reason in unbelievers but that some knowledge of the truth remains in them, which enable them to do deeds that are generically good.”

[M]ortal sin takes away sanctifying grace, but does not wholly corrupt the good of nature. Since therefore, unbelief is a mortal sin, unbelievers are without grace indeed, yet some good of nature remains in them. Consequently it is evident that unbelievers cannot do those good works which proceed from grace, namely, meritorious works. Yet they can, to a certain extent, do those good works for which the good of nature suffices. Hence it does not follow that they sin in everything they do. [A]n unbeliever can do a good deed in a matter which he does not refer to the end of his unbelief.

If this way of thinking did not infiltrate Protestantism to any significant degree, this was largely owing to the Protestant revival of Augustinian thinking in place of the more rationalistic approach of Aquinas. In Luther and especially in Calvin we see an emphasis on the total depravity of human nature, a condition brought about by original sin. Only with the grace of God is moral action possible, according to many leading Protestants, so atheists are incapable of performing moral actions.

It took a long time for this wall of prejudice to be dismantled. During the mid‐​seventeenth century the Levellers—the libertarians of their day—called for complete religious freedom, including freedom for atheists; but, generally speaking, the religious beliefs of Lilburne, Overton, Walwyn, and other Levellers were far from orthodox, and their position was not widely shared. Almost every prominent defender of religious toleration made exceptions for atheists.

Ironically perhaps, a glimmer of hope for atheists was provided by the Protestant hostility to Catholics. After all, the pope was the Antichrist, and it was Catholics, not atheists, who practiced “superstition” and who constituted the greatest threat to Protestants. So the question naturally arose: Are Catholics even worse, morally speaking, than atheists? As Protestant thinkers considered this question, they typically did so by asking which is worse—atheism or superstition? (In this literature “superstition” almost always signified Catholicism.) Over time many Protestants came to agree with the assessment of Francis Bacon (1561–1626). As much as this famous philosopher of science disliked atheism, he disliked “superstition” (i.e., Catholicism) even more. According to Bacon, it is better to have no opinion of God than to have a wrong opinion, one that is unworthy of him, for superstitious beliefs can easily generate harmful actions. As Bacon put it:

Atheism leaves a man to sense, to philosophy, to natural piety, to laws, to reputation, all which may be guides to an outward moral virtue, though religion were not, but superstition dismounts all these, and erecteth an absolute monarchy in the minds of men.

The most influential philosopher to defend the possibility of a society of atheists was Pierre Bayle (1647–1706), who had an enormous influence on the eighteenth‐​century Enlightenment. Although Bayle professed Calvinism, his epistemological skepticism (known as fideism) left him room to skewer many Christian doctrines with reason while maintaining that Christian beliefs must be accepted entirely on faith, despite their irrationalism. And this approach led to the widespread accusation that Bayle was actually an atheist who used his endorsement of Christianity to cover his tracks. (The sincerity of Bayle’s Christianity remains a topic of serious debate among scholars to this day. In my opinion, Bayle was probably a deist.)

Bayle’s moral rehabilitation of atheism was based on psychological and historical observations. On the psychological side, Bayle insisted that the fear and love of God “are not the sole springs of human action.”People behave morally for self‐​interested reasons, such as the desire to win the approval of others, and these natural motives influence the behavior of atheists as much as anyone else. Indeed, such motives are frequently stronger than the love and fear of God, as anyone can verify by looking within himself and at the everyday actions of others. It is therefore possible for an atheist, impelled by his natural temperament, to lead a virtuous life. Many atheists are sober, frugal people with a zeal for the public good and a desire to help their neighbors.

History, according to Bayle, “teaches us that…persons who denied either the existence or the providence of God, or the immortality of the soul, have nevertheless lived virtuous lives.” The historian has the obligation to represent people as they were, not as he thinks they should have been. Should facts be suppressed because some theologians believe they will diminish our horror of atheism? Should the historian serve as a lackey for ideological interests? No, said Bayle, it is the duty of the historian to do his best for objectivity. Deliberately to distort the historical record, even with the best of intentions, would be to violate “the fundamental laws of historical scholarship.”

Bayle’s critics were outraged by his claim that the vast majority of criminals believed in God. Indeed, according to Bayle, “of the many criminals who pass through the hands of the public executioner, there are none found to be atheists.” Bayle rejected the practice (discussed above) of referring to immoral people who profess to believe in God as “practical atheists.” Atheism, properly considered, pertains to the theoretical issue of belief, not to the practical matter of behavior. Those who insist that atheists are necessarily immoral should provide historical evidence for their claim.

Bayle became even more scandalous when he observed that the most wicked of all creatures, the devil, is “incapable of atheism.” The devil believes in God, as do his human disciples. Hence the most outrageously wicked people, those who have dedicated their lives to Satan, are not atheists, because belief in the devil and belief in God go hand in hand. The greatest evils, therefore, are “joined with a conviction of the existence of God.”

Thus did Bayle argue that “the worst villains are not atheists, and that most atheists whose names have come down to us have been virtuous according to ordinary standards.” Bayle counseled his many critics to examine this problem more carefully. Consider what would happen if moral behavior were impossible to all except the minority of people who have received the sanctifying grace of God. Society, which depends on peaceful cooperation, would be impossible if most people were incapable of respecting the rights of others; and the result would be “a general inundation that would destroy all monarchic, aristocratic, democratic, and other states.”

Bayle suggested that God “has everywhere spread a restraining grace” on humankind, on believer and atheist alike. In other words, the need for social cooperation provides natural incentives for virtuous actions, while vicious actions are checked by our desire for the approval and esteem of others. The social utility of virtue explains why atheists are fully capable of living virtuous lives.

Although Bayle’s call for religious toleration went further than that of John Locke and most other Protestants—Bayle included Catholics, for example—we should not suppose that Bayle favored the toleration of atheists; even his progressive views on atheism and morality did not lead him that far. In a passage that I find very difficult to reconcile with Bayle’s other statements on this topic, Bayle responded to those who might think that his call for freedom of conscience in philosophical and theological matters entailed freedom for atheists. This was not the case, Bayle assured his readers; his defense of conscience did not leave a door open “for Atheists to declaim against God and Religion, as much as they please.” Why? Bayle’s reason is very similar to that given by John Locke.

Because the Magistrate being, by the Eternal Law of Order, oblig’d to promote the publick Welfare and Security of all the Members of Society under his care, may and ought to punish those who sap or weaken the fundamental Laws of the State; and of this number we commonly reckon those who destroy the Belief of a Providence, and the Fear of divine Justice.

The atheist, according to Bayle, cannot legitimately appeal to the “inviolable Asylum of Conscience” because this would involve appealing to the will of God. Therefore, the atheist, being deprived of “this main Protection,” is “justly expos’d to the utmost Rigor of the Laws; and the moment he vends his Notions, after warning once given him, may be justly punish’d as a Mover of Sedition.”