There is no "mark of the cognitive"

So says Chemero.  Radical Embodied Cognitive Science, fn#8, p. 212.  But, what, more precisely, does this rejection amount to?

Does it mean that there is no difference between cognitive processes and non-cognitive processes?

Or does it merely mean that the difference cannot be defined?
Or does it merely mean that the difference cannot be spelled out in terms of necessary and sufficient conditions?
Or does it mean that there is no theory of the difference at all?
Or does it mean that we have no theory of the difference at this time?
Or what?