How did John Searle develop J.L. Austin’s speech act theory?

John Searle significantly extended and refined the speech act theory originally developed by his teacher, J.L. Austin. While Austin introduced the foundational concepts of locutionary, illocutionary, and perlocutionary acts, Searle provided a more systematic and rigorous framework.12

In his work Speech Acts: An Essay in the Philosophy of Language (1969), Searle proposed that speech acts could be defined by sets of rules—conditions that are individually necessary and collectively sufficient for performing an act sincerely and non-defectively. He identified three dimensions to classify these acts:2
* Illocutionary point: The purpose of the act.2
* Direction of fit: How the act relates to the world (e.g., "word-to-world" for statements or "world-to-word" for promises).2
* Expressed psychological state: The belief, desire, or intention expressed by the speaker.2

Using these dimensions, Searle created a taxonomy of five categories: assertives, directives, commissives, expressives, and declarations. Additionally, he introduced the concept of indirect speech acts, where one act is performed through another, and emphasized that speech acts rely on a "Network" of beliefs and a "Background" of human capacities.12