I begin by tracing some of the confusions regarding levels and

reduction

to a failure to distinguish two different principles according to which theories can be viewed as hierarchically arranged — epistemic authority and ontological constitution. I then argue that the notion of levels relevant to the debate between symbolic and connectionist paradigms of mental activity answers to neither of these models, but is rather correlative to the hierarchy of functional decompositions of cognitive tasks characteristic of

homuncular functionalism

. Finally, I suggest that the incommensurability of the intentional and extensional vocabularies constitutes a strong
prima facie reason to conclude that there is little likelihood of filling in the story of Bechtel''s

missing level

in such a way as to bridge the gap between such

homuncular functionalism

and his own model of mechanistic explanation.
Key words Epistemic authority - explanation - hierarchy - homuncular functionalism - intentionality - levels - measurement - mechanistic explanation - models - reduction - theories