In reexamining L. Karttunen's (1971: 'Some observations on factivity') distinction between full factives and semi-factives, O. stresses the pragmaticity of presuppositions. Full factives are further divided into positive factives (e.g. 'regret', which expresses the speaker's belief that the complement is true) and negative factives (e.g. 'pretend', which expresses the speaker's belief that the complement is not true). In the case of semi-factives (e.g. 'discover') it is argued that the speaker cannot have any positive belief that the complement is false, though he may positively believe that it is true or be neutral as to its truth. In the case of non-factives (e.g. 'believe', 'conclude') the speaker has no positive belief as to the truth of the complement.