The purpose of the paper is to show that semanticexternalism – the thesis that contents are notdetermined by ``individualistic'' features of mentalstates – is mistaken. Externalist thinking, it isargued, rests on two mistaken assumptions: theassumption that if there is an externalist wayof describing a situation the situation exemplifiesexternalism, and the assumption that cases in which adifference in the environment of an intentional stateentails a difference in the state's intentional objectare cases in which environmental factors determine thestate's content. Exposing these mistakes (...) leads to seethat the conditions that are required for thetruth of externalism are inconsistent. (shrink)