Full Idea
Functionalism has nothing positive to say about the intrinsic properties of mental states, only something about their relational properties.
Gist of Idea
Functionalism only discusses relational properties of mental states, not intrinsic properties
Source
E.J. Lowe (Introduction to the Philosophy of Mind [2000], Ch. 3)
Book Reference
Lowe,E.J.: 'Introduction to the Philosophy of Mind' [CUP 2000], p.67
A Reaction
This seems to me highly significant. All references to function (e.g. in Aristotle) invite the question of what enables something to have that function. Maybe the core question of philosophy of mind is whether mental states are intrinsic or relational.