Research into aphasia reveals new interactions between language and thought

(Universitat Pompeu Fabra - Barcelona) Knowledge of the facts is called factive knowledge. In the phrase 'He knows [that it is warm outside]', the embedded clause is assumed to be true. However, in the phrase 'It seems [that it is warm outside]', the embedded clause is presupposed to be false or counterfactive.
Source: EurekAlert! - Social and Behavioral Science - Category: International Medicine & Public Health Source Type: news