Full Idea
Grounding is something like metaphysical causation. Just as causation links the world across time, grounding links the world across levels. Grounding connects the more fundamental to the less fundamental, and thereby backs a certain form of explanation.
Gist of Idea
As causation links across time, grounding links the world across levels
Source
Jonathan Schaffer (Grounding, Transitivity and Contrastivity [2012], Intro)
Book Reference
'Metaphysical Grounding', ed/tr. Correia,F/Schnieder,B [CUP 2012], p.122
A Reaction
Obviously you need 'levels' for this, which we should take to be structural levels.