Okay, accepting that as a working assumption for the argument: What does? It's not things happening together that implies it, it's not things not happening together that implies it - negative and positive correlation respectively - so what is it?
The only other explanation I can think of is an understanding of the underlying mechanism, but what's that understanding based on? It can't be understandings of underlying mechanisms all the way down - you have to acquire the data from observation at some point.
Okay, accepting that as a working assumption for the argument: What does? It's not things happening together that implies it, it's not things not happening together that implies it - negative and positive correlation respectively - so what is it?
The only other explanation I can think of is an understanding of the underlying mechanism, but what's that understanding based on? It can't be understandings of underlying mechanisms all the way down - you have to acquire the data from observation at some point.