Impact and Overrule: two models of belief-assessment in Hume’s essay Of Miracles

The article seeks to explicate two models of belief-assessment that appear to be
operative in Hume’s essay Of Miracles and that correspond to the two parts of
the striking phrase «mutual destruction». One, which we tag «Impact», treats the
mutual interaction of bodies of evidence and testimony on the model of a collision
between two physical objects, and seeks to calculate the resultant quantities.
The other, which we tag «Overrule», operates on the quasi-judicial model of the
inadmissibility of certain evidence as tainted by its provenance or by its intrinsic
implausibility. The suggestion is made that the compresence of these two models
may help understand why it is so hard to identify the basic argument of Hume’s
essay; the question is left open of whether or not Hume has, perhaps in addition to
the two models presented, any «decisive» way of providing «an everlasting check
to all kinds of superstitious delusion».

Keywords: Miracle, David Hume, belief-assessment, probability, law of nature