Functionalism about mental phenomena must account for their multiple realizability. According to standard doctrine, this can be achieved by allowing our folk theory's realization formula to be multiply satisfied by distinct physical properties. If at all, uniqueness can then be restored by suitable relativization to populations or worlds. Recent arguments suggest that this is a dead end. Here the attempt is made to devise a novel type of functionalism that accounts for multiple realizability but rejects the standard doctrine and thus (...) proves immune to those arguments. The distinctive feature of this novel type of functionalism is its use of plural quantification in ramsification, which allows it to retain uniqueness of satisfaction despite multiple realizability while respecting naturalness requirements on physical properties. (shrink)