Chalmers (2011) argues for the following two principles: computational sufficiency and computational explanation. In this commentary I present two criticisms of Chalmers’ argument for the principle of computational sufficiency, which states that implementing the appropriate kind of computational structure suffices for possessing mentality. First, Chalmers only establishes that a system has its mental properties in virtue of the computations it performs in the trivial sense that any physical system can be described computationally to some arbitrary level of detail; further argumentation is required to show that the causal topology relevant to possessing a mind actually implements computations. Second, Chalmers' account rules out plausible ca...