Full Idea
For the emergentist why pain emerges when C-fibres are excited remains a mystery (a 'brute fact'), but such properties then take on a life of their own as 'downward causation'.
Gist of Idea
Emergent properties are 'brute facts' (inexplicable), but still cause things
Source
Jaegwon Kim (Philosophy of Mind [1996], p.229)
Book Reference
Kim,Jaegwon: 'Philosophy of Mind' [Westview 1998], p.229
A Reaction
I don't think there are any 'brute facts', except perhaps at the lowest level of physics. Whatever happened to the principle of sufficient reason? Is the mind like God - a causal source which is uncaused?