Discussion Questions on Humphreys' Theory of Explanation"

1.  Humphreys argues that specific probability values don't matter. What matters is only whether the factors cited make the explanandum event more probable.  Railton, in contrast, thinks that the specific probability value is very important in a fully elaborated explanation.  Who is right and why?

2.  What is Humphreys' contrast between linguistic and non-linguistic explanation.  What is a non-linguistic explanatory relation?

3.  Drinking a strong acid is not generally a healthy thing to do, but it might save one's life in a case in which one had already drunk a strong base.  In Humphreys' view would it explain why someone died to say "Astrid died because of drinking a strong acid, despite having her stomach pumped" (in a case in which Astrid did indeed drink a strong acid and did have her stomach pumped)?

4.  Suppose that in a period equal to its half life exactly 50.15% of the atoms in a small sample of an undisturbed radioactive element decayed.  What, according to Humphreys, would be the explanation?