Full Idea
Dennett identifies a hierarchy of minds running from 'Darwinian' (hard-wired solutions to problems), to 'Skinnerian' (trial-and-error), to 'Popperian' (anticipating possible experience), to 'Gregorian' (self-conscious representation, probably linguistic).
Gist of Idea
Minds are hard-wired, or trial-and-error, or experimental, or full self-aware
Source
report of Daniel C. Dennett (Kinds of Minds [1996]) by John Heil - Philosophy of Mind Ch.5
Book Reference
Heil,John: 'Philosophy of Mind' [Routledge 1998], p.162
A Reaction
Interesting. The concept of an experiment seems a major step (assessing reality against an internal map), and the ability to think about one's own thoughts certainly strikes me as the mark of a top level mind. Maybe that is the importance of language.