Abstract

Franz Brentano upheld the medieval Aristotelian doctrine of intentionality as a mark of the mental, distinguishing physical from psychological phenomena by the intentionality of the psychological and nonintentionality of the physical. But to implement, even to fully understand and appreciate Brentano’s thesis, it is necessary to know when intentionality does or does not obtain. The task of formulating satisfactory criteria of intentionality has proved elusive. The magnitude of difficulty is indicated by the number and variety of criteria proposed and defeated by counter examples. Intentionality may be a primitive irreducible property incapable of reductive conceptual analysis. But nonreductive criteriological characterizations of intentionality demonstrate an equally stubborn resistance to philosophical methods.