Essentially intentional actions are kinds of action that can only be done intentionally. Essentialism is the view that essentially intentional actions exist. Accidentalism is the view that essentialism is false. In my thesis, I develop and argue for naïve essentialism, a species of essentialism based on Michael Thompson’s naïve action theory. First, I present key features of naïve action theory and the broader Anscombean tradition, distinguish between essentially and accidentally intentional actions, and provide an argument for the existence of essentially (...) intentional actions. Second, I respond to three objections to my argument. Third, I argue that accidentalism is a reductive approach to action and faces some standard problems to such approaches. Fourth, I present three noteworthy implications of my defense of essentialism for the philosophy of mind and action. (shrink)