If a person X thinks that p, desires that p, believes that p, is angry at p, and so on, then he or she is described as having a propositional attitude to p . The term suggests that these aspects of mental life are well thought of in terms of a relation to a proposition, and this is not universally agreed. It suggests that knowing what someone believes, etc. is a matter of identifying an abstract object of their thought, rather than understanding his or her orientation towards more worldly objects.
Philosophy dictionary. Academic. 2011.