   The common legacy of Chisholm (1957) and Quine (1960) is the linguistic view of intentionality (accepted by e.g., Dennett 1969). Whether intensionality is indeed the defining criterion of intentionality, one can certainly question Brentano’s thesis that only mental phenomena exhibit intentionality by noticing that some non-mental things exhibit something very much like Brentano’s intentional inexistence, namely sentences of natural languages. Sentences of natural languages have meaning and by virtue of having meaning, they can be, just like states of mind, directed towards things other than themselves, some of which need not exist in space and time.  Sentences of natural languages, however, are non-mental things.