Daily Archives: 2018-07-29 00:14:05 UTC

Even a Bayesian Historian Can Slip Up! (once)

I argue that the interpretation of Bayesianism that I present here is the best explanation of the actual practices of historians.

— Tucker, Aviezer. 2009. Our Knowledge of the Past: A Philosophy of Historiography. Reissue edition. Cambridge University Press. p. 134

Aviezer Tucker

I have posted aspects of Aviezer Tucker’s discussion of how Bayesian reasoning best represents the way historians conduct their research but here I want to post a few details in Tucker’s chapter that I have not covered so far.

(Interjection: it is not strictly fair to call Aviezer Tucker a “Bayesian historian” because, as is clear from the opening quote, what he argues is that all historians, at least at their best and overall, employ Bayesian logic without perhaps realizing it.)

Tucker includes discussion of biblical criticism in his book but in his chapter on Bayesian methods he unfortunately contradicts himself. The contradiction can best be explained, I think, by appealing to the power of the Christian story to implant unquestioned assumptions into even the best of scholars. I could call that my hypothesis and suggest that the prior probability for it being so in many historians is quite high.

No doubt readers will recall my recent quotation from Tucker:

There have been attempts to use the full Bayesian formula to evaluate hypotheses about the past, for example, whether miracles happened or not (Earman, 2000, pp. 53–9). Despite Earman’s correct criticism of Hume (1988), both ask the same full Bayesian question:

“What is the probability that a certain miracle happened, given the testimonies to that effect and our scientific background knowledge?”

But this is not the kind of question biblical critics and historians ask. They ask,

“What is the best explanation of this set of documents that tells of a miracle of a certain kind?”

The center of research is the explanation of the evidence, not whether or not a literal interpretation of the evidence corresponds with what took place.

(Tucker, p. 99)

One explanation for the documents relating the miracles is that the miracles happened and were recorded. Other explanations can also come to mind.

No doubt because the question focused on miracles it was very easy for Tucker and countless others before and since to think of alternative hypotheses to explain the stories of miracles that have survived for our reading entertainment today.

The Slip Up

But look what happened to Tucker’s argument when he was faced with something that sounded more “historically plausible”: read more »