According to Fodor's informational approach, mental symbols have content by virtue of standing in certain nomic relations with their referents. These relations are sustained by computational mechanisms which enable the causal route linking mental symbols with the world. Fodor claims, however, that specifying the structure of those sustaining mechanisms is irrelevant for a theory of content. This paper argues that, on the contrary, without an account of the computational constraints under which those mechanisms operate, Fodor's theory is at best incomplete, and incapable of explaining what makes us the only known computing machine capable of bearing mental symbols so far.