Full Idea
An intelligible metaphysics will assign a central place to the idea of people (= speakers) with a location in public space and time.
Gist of Idea
Metaphysics requires the idea of people (speakers) located in space and time
Source
Donald Davidson (The Method of Truth in Metaphysics [1977], §III)
Book Reference
'Contemp Perspectives in Phil of Lang', ed/tr. French/Uehling/Wettstein [Minnesota 1979], p.303
A Reaction
The 'location' is the interesting bit, requiring people to be bodies, not abstractions. A big, plausible claim, but hard to prove.