Full Idea
Science attempts, by investigating basic structural traits, to find the nature, and thus the essence (in the philosophical sense) of the kind.
Gist of Idea
Science searches basic structures in search of essences
Source
Saul A. Kripke (Naming and Necessity lectures [1970], Lecture 3)
Book Reference
Kripke,Saul: 'Naming and Necessity' [Blackwell 1980], p.138
A Reaction
The 'necessity' of essences should be treated with caution, but this account of science strikes me as right, with the inbuilt assumption that the 'laws' are the consequence of the essences. A regularity becomes a law when it is explained by an essence.