Full Idea
'Deductive-nomological' explanation consists of two premises - a strict law with no exceptions and supporting deterministic counterfactuals, and a statement of an event which falls under the law - which together logically require the effect.
Gist of Idea
Strict laws make causation logically necessary
Source
Keith T. Maslin (Introduction to the Philosophy of Mind [2001], 7.4)
Book Reference
Maslin,Keith: 'An Introduction to the Philosophy of Mind' [Polity 2001], p.197