Full Idea
It would be harder to break P-and-Q implying P than the connection between cause and effect. This difference in strictness means it is more plausible that natural necessities include metaphysical necessities, than vice versa.
Gist of Idea
Causation is easier to disrupt than logic, so metaphysics is part of nature, not vice versa
Source
Kit Fine (The Varieties of Necessity [2002], 6)
Book Reference
Fine,Kit: 'Modality and Tense' [OUP 2005], p.259
A Reaction
I cannot see any a priori grounds for the claim that causation is more easily disrupted than logic. It seems to be based on the strategy of inferring possibilities from what can be imagined, which seems to me to lead to wild misunderstandings.