In the first part of the paper S. uses speech acts as a model to explain intentionality and to show that it is a phenomenon totally different from intensionality, even though sentences which specify intentional states are themselves intensional. Afterwards he makes use of the notion of intentionality to explain speech acts: intentionality is claimed to provide the foundation for linguistic acts; this is an attempt to provide a foundation for some of the criteria S. used in his classification or taxonomy of illocutionary acts.