Full Idea
For all the purposes of identity and individuation of things that belong to natural kinds..., it is enough to have regard for the lawlike propensities of members of the kind.
Gist of Idea
Lawlike propensities are enough to individuate natural kinds
Source
David Wiggins (Sameness and Substance Renewed [2001], 4.1)
Book Reference
Wiggins,David: 'Sameness and Substance Renewed' [CUP 2001], p.107
A Reaction
This may have got things in reverse, since it is hard to see how you could pick out any laws if you didn't assume the existence of natural kinds which were causing the regularities in the behaviour.