Symbol Grounding - Symbol Grounding and Brentano's Notion of Intentionality

Symbol Grounding and Brentano's Notion of Intentionality

"Intentionality" has been called the "mark of the mental" because of some observations by the philosopher Brentano to the effect that mental states always have an inherent, intended (mental) object or content toward which they are "directed": One sees something, wants something, believes something, desires something, understands something, means something etc.; and that something is always something one has in mind. Having a mental object is part of having anything in mind. Hence it is the mark of the mental. There are no "free-floating" mental states that do not also have a mental object. Even hallucinations and imaginings have an object, and even feeling depressed feels like something. Nor is the object the "external" physical object, when there is one. One may see a real chair, but the "intentional" object of one's "intentional state" is the mental chair one has in mind. (Yet another term for intentionality has been "aboutness" or "representationality": thoughts are always about something; they are (mental) "representations" of something; but that something is what it is that the thinker has in mind, not whatever external object may or may not correspond to it.)

If this all sounds like skating over the surface of a problem rather than a real break-through, then the foregoing description has had its intended effect: No, the problem of intentionality is not the symbol grounding problem; nor is grounding symbols the solution to the problem of intentionality. The symbols inside an autonomous dynamical symbol system that is able to pass the robotic Turing Test are grounded, in that, unlike in the case of an ungrounded symbol system, they do not depend on the mediation of the mind of an external interpreter to connect them to the external objects that they are interpretable (by the interpreter) as being "about"; the connection is autonomous, direct, and unmediated. But grounding is not meaning. Grounding is an input/output performance function. Grounding connects the sensory inputs from external objects to internal symbols and states occurring within an autonomous sensorimotor system, guiding the system's resulting processing and output.

Meaning, in contrast, is something mental. But to try to put a halt to the name-game of proliferating nonexplanatory synonyms for the mind/body problem without solving it (or, worse, implying that there is more than one mind/body problem), let us cite just one more thing that requires no further explication: feeling. The only thing that distinguishes an internal state that merely has grounding from one that has meaning is that it feels like something to be in the meaning state, whereas it does not feel like anything to be in the merely grounded functional state. Grounding is a functional matter; feeling is a felt matter. And that is the real source of Brentano's vexed peekaboo relation between "intentionality" and its internal "intentional object": All mental states, in addition to being the functional states of an autonomous dynamical system, are also feeling states: Feelings are not merely "functed," as all other physical states are; feelings are also felt.

Hence feeling is the real mark of the mental. But the symbol grounding problem is not the same as the mind/body problem, let alone a solution to it. The mind/body problem is actually the feeling/function problem: Symbol-grounding touches only its functional component. This does not detract from the importance of the symbol grounding problem, but just reflects that it is a keystone piece to the bigger puzzle called the mind.

Note: This article is based on an entry originally published in Nature/Macmillan Encyclopedia of Cognitive Science that has since been revised by the author and the Wikipedia community