I demonstrate that locking on, a key notion in Jerry Fodor's most recent theory of content, supplemented informational atomism (SIA), is cashed out in terms of asymmetric dependence, the central notion in his earlier theory of content. I use this result to argue that SIA is incompatible with the language of thought hypothesis because the constraints on the causal relations into which symbols can enter imposed by the theory of content preclude the causal relations needed between symbols for them to (...) serve as the elements of the medium of thought. (shrink)