Full Idea
According to the 'necessity' model of explanation, an explanation shows that the phenomenon in question had to occur.
Gist of Idea
An explanation shows why it was necessary that the effect occurred
Source
Peter Lipton (Inference to the Best Explanation (2nd) [2004], 02 'Reason')
Book Reference
Lipton,Peter: 'Inference to the Best Explanation (2nd ed)' [Routledge 2004], p.29
A Reaction
[He cites Glymour 1980] Lipton objects that the sort of necessity involved is too uncertain, can't account for the 'why-regress', and doesn't fit everyday explanation, like why we abandoned the football match.