One of Christopher Hitchens’s favorite evangelists of atheism is Pierre-Simon Laplace, the French mathematician. In God is Not Great, the Anglo-American polemicist takes special delight in retelling the story of how Laplace was asked by Napoleon why his great Treatise on Celestial Mechanics made no mention of God. “Sire, je n’avais pas besoin de cette hypothèse,” Laplace is supposed to have replied. (“Sire, I had no need of that hypothesis.”) This incident is the occasion for one of Hitchens’s diatribes against the Judeo-Christian God—though I am bewildered as to why a mere superfluous hypothesis should arouse his odium theologicum.

However, there are a few problems with the way that Hitchens uses this anecdote to bolster his argument. In the first place, Laplace was dealing with a specific scientific problem—the instability of the solar system—rather than with the general question of God’s place in nature. A century earlier, Isaac Newton, who was a theist of a very esoteric kind, had believed in the necessity of regular “corrections” by God to preserve cosmic equilibrium. Using much more accurate observational data, Laplace showed that no such interventions by the divine clockmaker were necessary. In his paper Does God Play Dice? Stephen Hawking commented: “I don’t think that Laplace was claiming that God didn’t exist. It is just that He doesn’t intervene, to break the laws of science.”

The second, far more serious problem, is that Laplace never used the words attributed to him by Hitchens. The encounter took place in 1802, before Napoleon had crowned himself emperor, when he was still First Consul of the French Republic, so Laplace would certainly not have addressed him as “Sire.” Laplace was in the company of Sir William Herschel, the English astronomer, who is our only eyewitness source for the meeting with Napoleon. According to Brandon Watson’s science website Houyhnhnm Land, the anecdote is found in Herschel’s diary of his visit to Paris, quoted in Constance Lubbock’s The Herschel Chronicle (Cambridge, 1933), p. 310:

The first Consul then asked a few questions relating to Astronomy and the construction of the heavens to which I made such answers as seemed to give him great satisfaction. He also addressed himself to Mr. Laplace on the same subject, and held a considerable argument with him in which he differed from that eminent mathematician. The difference was occasioned by an exclamation of the first Consul, who asked in a tone of exclamation or admiration (when we were speaking of the extent of the sidereal heavens): “And who is the author of all this!” Mons. De la Place wished to shew that a chain of natural causes would account for the construction and preservation of the wonderful system. This the first Consul rather opposed. Much may be said on the subject; by joining the arguments of both we shall be led to “Nature and nature’s God.”

Where, then, did the bon mot attributed to Laplace by Hitchens and countless others come from? Watson believes that it was invented by the popular historian E.T. Bell, whose well-known book Men of Mathematics appeared in 1937, just four years after Lubbock’s book. Bell gives no source for the Laplace quotation, and it appears to be one of many that he embellished or simply made up. Bell’s scholarship, incidentally, was unreliable in other ways, too: his book contains odious asides about the “aggressive clannishness” of Jewish academics.

Herschel’s account leaves no doubt that he, like Napoleon, believed in God. What, though, did Laplace believe? One of his two recent biographers, Charles Coulston Gillispie, does not even mention the discussion with Napoleon. Perhaps he regarded the question of Laplace’s views on God as a superfluous hypothesis. But Roger Hahn, another biographer of Laplace, found in his papers a 25-page manuscript detailing his objections to Catholicism, in particular to miracles and transubstantiation. (Clearly this manuscript was not intended for publication until after the author’s death.)

Laplace, who looks more and more like the Talleyrand of French science, enjoyed both Bonapartist and Bourbon patronage. Born in 1749, he was able to publish freely throughout the period from the ancien regime, the Republic, and the Empire through to the Restoration. Briefly Napoleon’s interior minister and president of his puppet senate, Laplace never hesitated to sign the warrant for the emperor’s deposition. He died a marquis, and was buried with great pomp, in 1827. If he was an atheist, he was certainly not prepared to risk his position in society by openly expressing his views. Laplace was a great man of science, but he was a great trimmer, as well. Hitchens and other militant atheists should look elsewhere for their heroes.