Maximality and Microphysical Supervenience

A property, F, is maximal iff, roughly, large parts of an F are not themselves Fs. Maximal properties are typically extrinsic, for their instantiation by x depends on what larger things x is part of. This makes trouble for a recent argument against microphysical supervenience by Trenton Merrick's. The argument assumes that consciousness is an intrinsic property, whereas consciousness is in fact maximal and extrinsic.