Full Idea
B-properties supervene naturally on A-properties if any two naturally possible situations with the same A-properties have the same B-properties.
Gist of Idea
Natural supervenience is when one set of properties is always accompanied by another set
Source
David J.Chalmers (The Conscious Mind [1996], 1.2.1)
Book Reference
Chalmers,David J.: 'The Conscious Mind' [OUP 1997], p.36
A Reaction
Since it is hard to imagine a healthy working brain failing to produce consciousness, given the current laws of nature, almost everyone (except extreme dualists) must concede that they are naturally supervenient. I wonder why they are.