Full Idea
If there are any genuine relations at all between spatio-temporal objects, then they are all either spatio-temporal or causal.
Gist of Idea
All relations between spatio-temporal objects are either spatio-temporal, or causal
Source
Craig Bourne (A Future for Presentism [2006], 3.III Pr4)
Book Reference
Bourne,Craig: 'A Future for Presentism' [OUP 2006], p.95
A Reaction
This sounds too easy, but I have wracked my brains for counterexamples and failed to find any. How about qualitative relations?
Related Idea
Idea 14009 It is a necessary condition for the existence of relations that both of the relata exist [Bourne]