Full Idea
The nature of explanation is such that ungrounded dispositions will always have to be posited in order to avoid a regress of explanation.
Gist of Idea
To avoid a regress in explanations, ungrounded dispositions will always have to be posited
Source
Stephen Mumford (Dispositions [1998], 10.6)
Book Reference
Mumford,Stephen: 'Dispositions' [OUP 1998], p.232
A Reaction
This seems to be right, but leaves it open to mock the proposals as 'virtus dormitiva' - empty place-holders that ground explanations but do no explanatory work. What else can be done, though?