Suppose we have an idea of what counts as communication, more precisely as a communicative event. Then we have the further task of dividing communicative events into successful and unsuccessful. Part of this task is to find a basis for this evaluation, i.e. appropriate properties of speaker and hearer. It is argued that success should be evaluated in terms of a relation between thought contents of speaker and hearer. This view is labelled ‘classical’, since it is justifiably attributable to both (...) Locke and Frege (section 2). Most of the paper is devoted to discussing competing contemporary views, such as behaviorist/pragmatist views (section 4), requirements of knowledge (section 5), of reliability (section 6) and that success should be defined in terms of public language semantics rather than in terms of thought content (section 7). (shrink)