Where does the cognitive system begin and end? Intracranialists maintain that the cognitive system is entirely identifiable with the biological central nervous system. Transcranialists, on the other hand, suggest that the cognitive system can extend beyond the biological CNS. In the second division of Supersizing the Mind, Clark defends the transcranial account against various objections. Of interest for this paper is Clark’s response to what he calls “asymmetry arguments.”Asymmetry arguments can be summarized as follows: subtract the props and aids, and (...) the organism may create replacements. But subtract the organism, and all cognitive activity ceases. Although I am sympathetic to Clark’s overall project, I find his response to the asymmetry arguments inadequate in light of his responses to other objections. For this reason, I maintain that Clark’s response requires revision. By adopting a process metaphysics and appealing to mereological dependencies, I believe that Clark can provide a substantive response to asymmetry arguments that is consistent with his overall theory. This paper unfolds as follows: after summarizing Clark’s response to the asymmetry objection in, I will argue that his response is unsuccessful in. My argument hinges on the claim that Clark does not take into account the full intent of Rupert’s asymmetry argument. In I modify Clark’s response by appealing to mereology and the asymmetrical dependencies found therein. I conclude in that this modification provides Clark with an adequate response to the asymmetry argument and is consistent with his overall transcranialist account. The further question of whether this account assists Clark in responding to other intracranialist objections is beyond the scope of this paper. (shrink)