A “representation” in the primary sense is thus an act of representing (that things are thus-and-so). (E.g., “Smith objected to Hill’s representation of the facts of the case.”) In a secondary we may speak of the vehicle through which this representing-as-thus-and-so takes place as a “representation”. It is in this sense, for example, that we speak of token symbols and diagrams as representations. To the extent that there are features of the vehicle that allow vehicles of that kind to be used systematically to represent things as being thus-and-so, we may apply the term ‘representation’ to the type as well as the token. (This distinction is necessary because some types of representation-tokens, such as scribbled diagrams, may not fall into representational types, while others, such as symbols, typically do so.) We may use the notion of “representing things as being thus-and-so” so broadly that it can apply both to cases that are communicative (A represents things as being thus-and-so to B by uttering sentence S) and to cases that are purely mental (A represents things as being thus-and-so (to herself) in the sense of, say, judging that they are thus-and so). The notions of “representing” and “representation”, one should note, are mental and intentional through and through. These notions of “representation” can be applied only to beings that think and to the representational tokens and types that they employ as aids in thinking and communication.
seated at a table, ordering, and paying the bill. The “dynamic principles” will take the form of something like Shanck’s scripts, which track characteristic temporal patterns of states and transitions. Models in Perceptual Modules: Modules utilized in perception, such as layers of V4 involved in color perception, may also be viewed as representational systems. A system for color, for example produces arrays of color-representations in a retinotopic map, tracking arrangements of chromatic properties within the visual field. Such a model involves a spatial arrangement of units, with an internal geometry and topology, and each unit is capable of a range of states modeled by the color solid. Areas later in the perceptual stream used to represent spatial geometry provide a model describable in terms of geometric rules that is used for representing objects in space. A representational system defines a possibility space for possible token representations. A particular gravitational model rigorously defines a way of thinking or speaking about the locations, motions and dynamic interactions of bodies in space over time. This, in turn, provides the resources for describing a particular set of bodies (e.g., the Sun and the Earth) in terms of position, mass, and inertia, and for calculating the resultant gravitational component of their dynamics. A restaurant script defines a set of possible events and actions (and thoughts and utterances about them) that are on-script. This provides the resources for describing and understanding a variety of particular occasions of dining in which
cognition must have some mental form – one or more representational systems. The use of these systems is not limited to cognition through online perception, but can take the form of various kinds of imagining as well. These are certainly not limited to perspectives that one has actually occupied in the world – e.g., I can always ask “What would that look like if I moved over there?” Even more plainly, they are not limited to perspectives I am presently in. But they are also not limited to perspectives that I really could be in. Perhaps I can now be in a position to look down (say, from a crane or a hot air ballon) upon a house under construction in ways most generations of my ancestors could not. But I cannot really be in a position to “see” what the organelles of a cell look like from a position in-between them – though I can certainly imagine it, and use that imagining to explore things about it. Let us now try to be a bit more careful and precise. I am suggesting that I have mental models of such things as my childhood home. (Perhaps there is a single integrated model of it in my mind, perhaps a constellation of models of parts and aspects of it.) But by this I do not mean that “having a mental model” means that there “is something” in my mind that has the same geometric features as my house. That, indeed, would strike me as a category error. What, then, do I mean by “having a model” of my house in my mind? One thing I mean is that there is something – call it X – in my mind that allows me to store and explore features of the house itself. And in these examples, I am particularly concerned with forms of “exploring features” that bear a good deal of phenomenological resemblance to what I might do to extract information about the
model of physical space in general, one which is different from other models that employ distinct geometric or topological principles. It is both an abstract model and a modeling system for providing representations and models of more particular states of affairs and processes. A model of human anatomy, by contrast, is generally not useful as a kind of production system for various anatomical configurations, but as a model of the standard human anatomy. It may be that some such models have parts that can be modified, removed or rearranged to model nonstandard configurations, but to the best of my knowledge this is not its standard or preferred use. It can, however, be used to model specific conditions and procedures, such as the anatomical consequences of removing a bone or organ. we draw the boundaries around the term ‘model’ here is in part a matter of deciding what terminology will provide the most useful set of theoretical resources. I am inclined to use the term in fashion that treats “models” as offering a space of representational possibilities of states of affairs. But this is a very broad usage, allowing models of varying degrees of generality and abstraction. Model A may provide the representational space for B, in which case B may be said to be a representation within the representational system afforded by A. But B may nevertheless itself be a model if it defines a space of representations of its own. Even a model of a particular may do this: a scale model of a car or train may be capable of being manipulated to represent various states – say, doors open or doors closed, hooked to the engine or decoupled – and may allow other sorts of representations as well, such as one of the ratio between the length and width of the
additionally link these two thoughts as thoughts about the same object? To put it crudely, how is it that we do not simply think “an X” at T1 and “an X” (or “another X”) at T2, but rather think at T2 of “the selfsame X we thought about at T1”? The second, and more fundamental, issue is how we are able to think, even in a single thought at a single moment, not merely of this property and that property being presented, but of a single thing that has both properties? We are clearly able to do so, but a psychology like Hume’s, whose resources are limited to the presentation of individual impressions and ideas, cannot explain how we are able to do so. The Binding Problem A related problem occurs in neuroscience. Philosophers Aristotle traditionally assumed that, in addition to the various sensory modalities – sight, hearing, touch, smell, taste – there must be an additional faculty, the sensus communus or “common sense”, where the deliverances of these were fused together into a polymodal representation of an object. Scientific study of the brain has revealed various neuroanatomical areas corresponding to the various sensory modalities, but not of a sensus communus where “it all comes together”. Indeed, our contemporary understanding of the brain only makes things more complicated: not only is there no brain area where sight comes together with all the other modalities in a single representation, there are distinct areas for different aspects of vision: color, form, and motion.