Full Idea
Goodman's central idea was: 'If that match had been scratched, it would have lighted' is true if there are suitable truths from which, with the antecedent, the consequent can be inferred by means of a logical, or more typically natural, law.
Gist of Idea
Counterfactuals are true if logical or natural laws imply the consequence
Source
report of Nelson Goodman (The Problem of Counterfactual Conditionals [1947]) by Ian McFetridge - Logical Necessity: Some Issues §4
Book Reference
-: 'Aristotelian Society' [], p.151
A Reaction
Goodman then discusses the problem of identifying the natural laws, and identifying the suitable truths. I'm inclined to think counterfactuals are vaguer than that; they are plausible if coherent reasons can be offered for the inference.
Related Idea
Idea 8431 Problems with Goodman's view of counterfactuals led to a radical approach from Stalnaker and Lewis [Horwich]