Did David Hume “Banish” Miracles?

Keeping History Safe

In the cold morning air with the sun not yet over the ridge, the place to begin preparation for summiting Mount Darwin is to ponder the reasonableness of miracles. Many Totalizers would like to ban miracles from university consideration and inquiry. Trouble is: human history is awash with credible people reporting miracles.

Modern academic tradition tends to try and maintain order. For historians it behooves us professionally to avoid accounts of alleged spiritual events. We find comfort in a little logical gymnastics that keeps history safe for us to wander in, a deceptively formulaic avoidance method that helps us avoid what people are telling us about extraordinary events in the past.

David Hume popularly articulated this logical gymnastics in an essay titled “Of Miracles” that was eventually printed in Enquires Concerning Human Understanding (1748). “I flatter myself,” Hume triumphantly proclaimed, “that I have discovered an argument . . . which, if just, will, with the wise and learned, be an everlasting check to all kinds of superstitious delusion, and consequently, will be useful as long as the world endures.”

His everlasting check on superstition begins with a circular argument that because miracles can’t happen, a reasonable person should not even listen to reports of them. Hume taught that though the normal job of a historian was to listen to the testimony that comes down to us from the past, there is a point at which you can close your ears. Hume knew that historical testimony can get wild, so he came up with a way to domesticate the wildness, a way to make history a zoo rather than allow it to be a jungle. His “Of Miracles” has been tremendously influential in the discipline of human history over the last two hundred and fifty years, not because his ideas are strong, but because his ideas are useful. Get rid of “superstitious delusions,” and the discipline of history can be turned from a safari into a form of home economics. Hume’s domestication of history is seductively simple. Instead of following the Aristotelian tradition of linking the credibility of hard-to-believe testimony to the credibility of the testifier, Hume recommended disregarding the testifier and focusing only on the testimony. This effectively removed the persuasive power from hard-to-believe testimony. Miracles need the credibility of an eyewitness in order to have persuasive power. Hume cut the power source from the unwanted testimony.

Essentially, Hume adopted the modeling technique that Darwin later used and is best seen in Global Positioning System (GPS) units. Hume recommended gathering testimony from the past and every region to create a general model of what humans generally experience. Using this mass of information, one should generalize standards of common experience. Now if anyone reports a miracle, the alleged event can’t be true because it does not conform to the generalized standards of common experience. (Of course, Hume had already refused to allow that any reports of miracles could be used even to generalize common experience.) It’s tricky. Its logic is circular. But it works to weed out awkward, quirky information. It is as if a domineering GPS unit created a sphere to serve as an abstraction for the earth, then insisted that the earth can’t have wobbling poles and flattening in the upper latitudes because the sphere in the GPS shows it can’t be true. Given a useful and trustworthy GPS, don’t listen to a scientist who might tell you something different than what the GPS tells you.

The circularity of this argument has been noted ever since Hume first proposed it, but Hume was a good writer and said what a lot of people wanted to hear. Miracles are impossible so miracle reports can’t be true. Don’t even listen to reports of them.

Balancing Likelihoods

Also embedded in Hume’s essay is the awkward “rule of logic,” most often called “Balancing Likelihoods.” By combining math and logic in an odd way, Hume’s “Of Miracles “ offered another way for historians to avoid thinking about miracles. Balancing Likelihoods has many names but is probably best stated by David Hackett Fischer, in hisHistorians’ Fallacies: Toward a Logic of Historical Thought, as “the rule of probability:”

[A]ll inferences from empirical evidence are probabilistic. It is not, therefore, sufficient to demonstrate merely that A was possibly the case. A historian must determine, as best he can, the probability of A in relation to the probability of alternatives. In the same fashion he cannot disprove A by demonstrating that not-A was possible, but only by demonstrating that not-A was more probable than A. This is the rule of probability.

This seems to be practical but is impossible. Balancing Likelihoods, in the way described by Fischer, cannot be used by historians in any normal practice. It is a talisman to keep history mentally safe from the wildness that is reported to exist. Logicians, especially mathematicians, have long criticized intellectual constructions like this. The “probability” that Fischer writes about is seemingly mathematical, but the math is simply implied to give a sense of strength to human feelings.

Before Hume wrote “Of Miracles” probabilistic logic had been advancing rapidly and there was a great hope that mathematical analogies would strengthen human thinking—even Christian apologetics. “Pascal’s Wager,” the most famous mathematical apologetic from the seventeenth century, equated eternal salvation with mathematical infinity and then applied it to a gambling formula. Antoine Arnauld, in The Port-Royal Logic (1662), and John Locke, in hisEssay Concerning Human Understanding (1690) and Discourse on Miracles (1706), carried probabilistic math and logic into the handling of reported miracles. A half-century later, however, Hume reacted against Arnauld and Locke’s teachings that mathematical analogies could help in the discussion of the credibility of miracles. Hume insisted that to handle a reported miracle, a historian had to create two separate ratios, pro and con, for believability. The ratios were then to be weighed against each other. This is Fischer’s “rule of probability” quoted above. In the language of Hume’s era, this was proclaimed as the “calculus of good sense.”

Lorraine Daston, in Classical Probability in the Enlightenment (1988), offers an excellent study of Hume and the many eighteenth-century mathematicians who wanted to help bring rigorous quantitative thinking to what today would be called the humanities. Daston writes that by the 1840s, mathematicians realized that “the ‘calculus of good sense’ had become antithetical to good sense,” and that today most of what these early probabilists were trying to do is considered “patently absurd.”

In 1901, one of America’s preeminent philosopher-mathematician-logicians, Charles Sanders Peirce, wrote three essays attacking the way historians had adopted Hume’s bad logic: “A Preliminary Chapter, Toward an Examination of Hume’s Argument Against Miracles, in its Logic and in its History,” “Hume’s Arguments Against Miracles, and the Idea of Natural Law,” and “On the Logic of Drawing History from Ancient Documents especially from Testimonies.” Peirce showed that historians are in error when they talk of judging testimony by balancing probabilities because “in a scientific sense, there are no ‘probabilities’ to be judged.”

Probability, Peirce wrote, “is the ratio of the frequency of occurrence of a specific event to a generic event.” A testimony “is neither a specific event, nor a generic event, but an individual event.” Peirce further pointed out that what people were justifying by claiming Balancing Likelihoods was really simply relating “what they prefer to do” to what they don’t prefer. “Likelihood is merely a reflection of our preconceived ideas.”

Historians like me who teach in universities about the reasonable credibility of Jesus’ resurrection need to be students of Peirce not Hume on the subject of assessing the credibility of reports that come down to us from ancient history. Dealing wisely with reports of events verging on the incredible is just part of the normal job of being grounded in the social study of our complex human past.

“Come to history as a doubter,” Richard Marius advises in a historical methods manual. “Skepticism is one of the historian’s finest qualities. Historians don’t trust their sources. . . . Nothing is quite so destructive to a historian’s reputation as to present conclusions that prove gullibility.”

But Marius is wrong. In practice, historians have to trust more than doubt. In practice, historians, especially ancient historians, can’t rely on doubting. Historians have to be close listeners, discerning listeners, wise listeners, who sometimes have to make harmonies and stretch for belief.