Full Idea
Each disposition, in my view, is a physical state or mechanism. ...In some cases nowadays we understand the physical details and set them forth explicitly in terms of the arrangement and interaction of small bodies. This replaces the old disposition.
Gist of Idea
Dispositions are physical states of mechanism; when known, these replace the old disposition term
Source
Willard Quine (The Roots of Reference [1990], p.11), quoted by Stephen Mumford - Dispositions 01.3
Book Reference
Mumford,Stephen: 'Dispositions' [OUP 1998], p.13
A Reaction
A challenge to the dispositions and powers view of nature, one which rests on the 'categorical' structural properties, rather than the 'hypothetical' dispositions. But can we define a mechanism without mentioning its powers?