As Frege remarked before Austin, and Aristotle before Frege: language is not made of descriptive sentences only. A task traditionally assigned to logicians is to explain how to distinguish those sentences from others.
Benoist, J. (2002)., Non-objectifying acts, in D. Zahavi & F. Stjernfelt (eds.), One hundred years of phenomenology, Dordrecht, Kluwer, pp. 41-49.
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