All information processing entails computation, or, if R. A. Fisher had been a cognitive scientist ...

We argue that the dynamical and computational hypotheses are compatible and in fact need each other: they are about different aspects of cognition. Ho wever, only computationalism is about the information processing aspect. We then argue that any form of information processing relying on matching and comparing, as cognition does, must use discrete representations and comput ations defined over them.