 Predictably, such theories face various difficulties—so none provide a decisive case for EXT. Yet the foremost arguments for the view are not so parochial. These arguments instead rest on various thought experiments, purporting to show that internally identical subjects can host different thought contents, solely because of environmental differences (Putnam 1973; 1975, McGinn 1977, Stich 1978, Burge 1979; 1982; 1986). If the thought experiments are right about this, then internal states do not wholly determine thought content. The environment would play a part as well.