An interdisciplinary approach to intentionality (directedness towards objects) is introduced that treats intentionality primarily as a feature of goal-directed behaviour rather than of mental states. Within a hierarchical framework, four levels of intentionality with increasing complexity are distinguished, which accord to cognitive capacities human beings acquire during ontogenetic development, i.e. the framework proceeds “from the beginning onward rather than from the bottom up or the top down” (Gallagher 2005). Recent work in neurophysiology and developmental psychology shall be integrated in the philosophical descriptions of the varieties of directedness.
The most basic and “biologically primitive” (Searle 1983) forms of intentionality are (non-epistemic) perception and motor intentional activities such as grasping an object. In order to characterize this basic level, the “dual model” of human visual processing is incorporated (Milner & Goodale 1995, Jacob & Jeannerod 2003). Among the essential features of such intentional behaviour is embodiment (Clark 1997).
The second level is characterized by the infant’s capacity for joint attention. On a third level, the infant can make partial use of the imagination and become partially independent from current perceptual contexts (e.g. pretend play), and interpret others as intentional agents. Finally, the child can explicitly represent other people’s mental representations (theory-of-mind).