Full Idea
It is not denied that statements attributing dispositions and/or powers to objects are often true. But the truth-makers or ontological ground for such statements must always be found in the actual, or categorical, properties of the objects involved.
Gist of Idea
Dispositions exist, but their truth-makers are actual or categorical properties
Source
David M. Armstrong (What is a Law of Nature? [1983], 01.3)
Book Reference
Armstrong,D.M.: 'What is a Law of Nature?' [CUP 1985], p.9
A Reaction
This is the big debate in the topic of powers. I love powers, but you always think there must be 'something' which has the power. Could reality entirely consist of powers? See Fetzer.
Related Ideas
Idea 17666 Actualism means that ontology cannot contain what is merely physically possible [Armstrong]
Idea 15797 All structures are dispositional, objects are dispositions sets, and events manifest dispositions [Fetzer]