The 72-witness rule

James Franklin reports (at pp. 13-14 in his book The Science of Conjecture: Evidence and Probability before Pascal (2001)) that the False Decretals, a mish-mash of things compiled ca. 850 A.D., contain a passage asserting that a "bishop should not be condemned except with seventy-two witnesses." About this and some similar rules for defendants of lesser stature Franklin writes:

It is the world's first quantitative theory of probability. Which shows why being quantitative about probability is not necessarily a good thing.