 Functionalists have replied to these worries in different ways. Many just deny the intuition behind the objection, and maintain that even the strictest conceptual analyses of our intentional terms and concepts purport to define them in terms of their bona-fide causal roles, and that any norms they reflect are explanatory rather than prescriptive. They argue, that is, that if these generalizations are idealizations, they are the sort of idealizations that occur in any scientific theory: just as Boyle's Law depicts the relations between the temperature, pressure, and volume of a gas under certain ideal experimental conditions, our a priori theory of the mind consists of descriptions of what normal humans would do under (physically specifiable) ideal conditions, not prescriptions as to what they should, or are rationally required, to do.