Full Idea
Proponents of multiple realisability regard it as vital to distinguish realised, higher-level properties from their lower-level realisers.
Clarification
'Multiple realisability' is (e.g.) humans and martians producing pain in quite different ways
Gist of Idea
'Multiple realisability' needs to clearly distinguish low-level realisers from what is realised
Source
John Heil (Philosophy of Mind [1998], Ch.6)
Book Reference
Heil,John: 'Philosophy of Mind' [Routledge 1998], p.200
A Reaction
So that the very idea of 'multiple realisability' begs the question. Minds are private, so it is never clear what has been realised, especially in non-linguistic brains.