Full Idea
It is said that a good explanation ought to produce understanding, ...but this just says that a good explanation produces possession of that which it provide, so this desideratum is empty. It adds nothing to our understanding of explanation.
Gist of Idea
Does a good explanation produce understanding? That claim is just empty
Source
David Lewis (Causal Explanation [1986], V)
Book Reference
Lewis,David: 'Philosophical Papers Vol.2' [OUP 1986], p.228
A Reaction
I am not convinced by this dismissal. If you are looking for a test of whether an explanation is good, the announcement that the participants feel they have achieved a good understanding sounds like success.
Related Idea
Idea 16806 An explanation is what is added to knowledge to yield understanding [Lipton]