The mathematics of a system of interlocking differential equations can (at least in simple cases) accurately capture the way two or more systems engage in a continuous, real-time, and effectively instantaneous dance of mutual codetermining interaction. But it is a burden insofar as it threatens to obscure the specifically intelligence-based route to evolutionary success. That route involves the ability to become apprised of information concerning our surroundings and to use that information as a guide to present and future action. As soon as we embrace the notion of the brain as the principal (though not the only) seat of information-processing activity, we area already seeing it as fundamentally different from, say, the flow of a river or the activity of a volcano.
This seems to me to point out that the dynamical systems approach to extended cognition needs to take into account a distinction between cognitive processes (which Clark here treats as information processing processes) and other non-cognitive causal processes. I couldn’t agree more. In fact, this is one way of making one of my favorite points, namely, that the advocates of ExCog in general need a plausible theory for distinguishing cognitive and non-cognitive processing. They need a mark of the cognitive.