[T]he categories of intentionality are nothing more nor less than the metalinguistic categories in terms of which we talk epistemically about overt speech as they appear in the framework of thoughts construed on the model of over speech.
Wilfrid Sellars (1912–1989), U.S. professor of philosophy; Yale (Pittsburgh). Volume II, ed. Herbert Feigl, Michael Scriven, and Grover Maxwell, p.522. Minnesota Studies in the Philosophy of Science, "Chisholm-Sellars Correspondence on Intentionality," University of Minnesota Press (1958).