Mind-Brain and Spatial Extension

Our mental states seem to elicit certain paradoxes; for example, how can it be that my mental state can be abstract yet located where my body is? The mind's temporal nature, on the other hand, seems more straight forward. The mind came into existence at a point in time, thoughts follow one another in succession, etc.

Colin McGinn, a prominent philosopher of mind, makes the case for the non-spatial nature of mental properties:

"It is hard to deny that Descartes was tapping into our ordinary understanding of the nature of mental phenomena when he formulated the distinction between mind and body in this way - our consciousness does indeed present itself as non-spatial in character. Consider a visual experience, E, as of a yellow flash. Associated with E in the cortex is a complex of neural structures and events, N, which does admit of spatial description. N occurs, say, an inch from the back of the head; it extends over some specific area of the cortex; it has some kind of configuration or contour; it is composed of spatial parts that aggregate into a structured whole; it exists in three spatial dimensions; it excludes other neural complexes from its spatial location. N is a regular denizen of space, as much as any other physical entity. But E seems not to have any of these spatial characteristics: it is not located at any specific place; it takes up no particular volume of space; it has no shape; it is not made up of spatially distributed parts; it has no spatial dimensionality; it is not solid. Even to ask for its spatial properties is to commit some sort of category mistake, analogous to asking for the spatial properties of numbers. E seems not to be the kind of thing that falls under spatial predicates. It falls under temporal predicates and it can obviously be described in other ways - by specifying its owner, its intentional content, its phenomenal character - but it resists being cast as a regular inhabitant of the space we see around us and within which the material world has its existence. Spatial occupancy is not (at least on the face of it) the mind's preferred mode of being." (1995)

According to McGinn, our mental states do not warrant the same spatial talk that we make of physical states. Does it make sense for me to say that my smelling the coffee first thing in the morning is located 2 cm above my right ear? But we talk about the spatial dimensions of physical objects all the time. It makes just as much sense to talk about the spatial properties of numbers as it does mental states.

But if our intuitions strongly tell us that mental states are non-extended in space then it is also quite obvious that they are, nonetheless, located in space. To borrow McGinn's example, my act of perceiving, although non-extended in space, is located where my brain and eyes are and not at the Grand Canyon. This has troubled some philosophers like Jerry Fodor who think its a strike against dualism:

"The chief drawback of dualism is its failure to account adequately for mental causation. If the mind is non-physical, it has no position in physical space. How then, can a mental cause give rise to a behavioural effect that has a position in space? To put it another way, how can the nonphysical give rise to the physical without violating the laws of conservation of mass, of energy and of momentum" (1994: 25)

The hylomorphist can respond to this by pointing to individual substances which seem to contradict this. Recall in earlier posts I pointed out that the form is just the organisation of the matter. Contrary to dualism, the form is not an additional substance to the matter. Take the parts of a disassembled table. Do they weigh anything more after assembly? No (this point is also made by Kathrin Koslicki, 2008: 177). Is the total length or surface volume of the parts anymore on assembly than before? Of course not. But it is hard to deny that something new has come into existence when a table is assembled. The table has been added to our ontological inventory of items in the universe.

This must mean that the form is a non-physical thing that is non-extended in space and yet it is located in space. The form does not exist at any one particular point on the object but is distributed throughout the entirety of that object as it is the organisational state of the matter.  Just as the abstract proposition that is embodied in the word 'cat' is distributed throughout the inscription and order of its letters.

Fodor finds it incredulous that mental states that are non-physical can act on bodily states that are located in space. But if we take forms to supervene on matter organised in a particular way then we do not have to talk as if the mental is 'acting on' or 'causing' the physical. For example, sets supervene on their members (Armstrong 1989: 11), yet we would not say that sets 'act on' their members. A set and its members forms a metaphysical unity of one entity over many (at least two). Indeed, the constitution relation, like marble relative to a statue, counts as supervenience (Crane 2001: 58).

Thus there are paradigmatic examples, like propositions, sets, and artefacts, where it is readily apparent how a non-physical thing can be located in space but non-extended. But it requires seeing forms (which is equated with the mind for Aristotelians) as the non-physical, organisers of bodies as a whole.