Full Idea
There is a distinction between powers, and the properties in virtue of which things have they powers they have (n8: 'in virtue of' means that there is a lawlike truth, which turns out to be the properties entailing the powers).
Gist of Idea
Things have powers in virtue of (which are entailed by) their properties
Source
Sydney Shoemaker (Causality and Properties [1980], §03)
Book Reference
Shoemaker,Sydney: 'Identity, Cause and Mind' [OUP 2003], p.211
A Reaction
To me this is an ontology which rests something very clear (a power) on something very indeterminate (a 'property').