Full Idea
What theoretical scientific explanation aims at is an objective kind of insight that is achieved by a systematic unification, by exhibiting the phenomena as manifestations of common underlying structures and processes that conform to testable principles.
Gist of Idea
Scientific explanation aims at a unifying account of underlying structures and processes
Source
Carl Hempel (Philosophy of Natural Science [1967], p.83), quoted by Laurence Bonjour - The Structure of Empirical Knowledge 5.3
Book Reference
Bonjour,Laurence: 'The Structure of Empirical Knowledge' [Harvard 1985], p.99
A Reaction
This is a pretty good statement of scientific essentialism, and structures and processes are what I take Aristotle to have had in mind when he sought 'what it is to be that thing'. Structures and processes give stability and powers.