Abstract

Using his two-dimensional semantics, I demonstrate that David Chalmers’s 2010 ‘two-dimensional argument against materialism’ is sound only if a wide swath of reductive physicalist theses – crucially, those involving identity and other intrinsic reductive relations – are inconceivable. 2DA therefore begs the question against its opponents and undermines its argumentative relevance. Comparisons are drawn to similar arguments in Marton and Sturgeon; the present account differs in its formal and philosophical simplicity, as well as its specific application to reductivist doctrines beyond the ineffective and merely supervenient.