‘Explanation and expertise in a fragile world’

Imagine two worlds. In one, causal relations and mechanisms hold reliably across many cases; laws are unchanging. In the second world, by contrast, these things are fragile, holding only intermittently and unpredictably. Just because one thing causes another over there doesn’t mean that it causes it over here. I claim that much of our world is like the second world – target relations are fragile. I will discuss the consequences of this, zeroing in on two issues in particular: 1) mechanistic explanation, and 2) scientific expertise.