Abstract
Social externalism is a thesis about theindividuation-conditionsof thoughts. Actually, the thesis applies only to a special category of ‘trained’ thoughts, thoughts which issue from trained thinking. It isn't that the thinker of such a thought has to have had special training about thesubject-matter. It is rather that he or she needs to have acquired certain basic linguistic skills and values. For trained thoughts are thoughts whose contents are tailored to the demands of communication. Social externalism, as I understand it, says that people who are competent in a public language are equipped to have certain thoughts whose contents are fixed (in part) by the lexical semantic norms of their language.