NoR: 1.1. Layers of Representation.

This is one of a series of posts setting out my work on the Nature of Representation. You can view the whole series by following this link. 

The experience of running downhill. The recollection of the coffee you drank this morning. The belief that everything is grounded in the physical. The desire to stop eating meat. A photograph of your mother. The words “it’s behind you”.

All share a common feature. They are all representations of something else, they have the spooky feature of “aboutness”. The photograph is a thing that can be put in an album and stored on a shelf. But it represents something else entirely—an individual human being. The belief (let’s assume) is a certain configuration of your brain, but it represents a general feature that that the world we inhabit as a whole might have or fail to have. We have one thing (states of our brain, other biological systems or artefacts) representing quite different things: hills, coffee, monsters, or whatever. You won’t be able to think of anything that can’t be represented (suppose you were able to: then in thinking about it, you’d be representing it).

I want to know about the nature of representation—what representation is, how it gets generated, and how different kinds of representation relate to one another. What is the basis for representation and how does it arise out of (“get grounded in”, “reduce to”) that basis?

In this series of posts, I’m going to present an answer to that question. Here is the overarching structure of how the story goes.

(1) The most primitive kind of representation is the “aboutness” we find in perception and action/intention—the two most basic modes in which we and the world interact. This layer of representation consists in states of our head which if functioning properly are produced by particular aspects of our environment (perception) or bring about changes in our environment (action/intention). It is to be analyzed, say I, into a combination of teleological (“functioning properly”) and causal (“produced by/bringing about”) features of things. We can understand how this kind of representation can exist in a fundamentally physical world so long as we have an independent, illuminating grip on functions and causation.

(2) The next kind of representation is the “aboutness” of (degrees of) belief and desire. Where the representational content of perception and action was tightly bound to visible or manipulable features of the immediate environment, beliefs and desires can represent anything (certainly anything you can think of). This layer of representation consists in states of our head which (inter alia) update in response to the information that comes in from perceptual states, and which in combination lead to the formation of states of intention. It is to be analyzed, say I, by giving a story about the correct belief/desire interpretation of the agent—with the critical question being giving an illuminating gloss on what makes an interpretation “correct”. This is where the layering comes in. In my telling of the story, the correct interpretation of an agent is that one which makes their actions/intentions, given their perceptual evidence, most reasonable. Accordingly, the story about belief and desire presupposes a prior and independent story about perception and action. We can understand how the belief and desire kinds of representation can exist in a fundamentally physical world so long as we have an independent illuminating grip on “reasonableness” and so long as the first layer of representation is available to cash out appeals to perception and action/intention.

(3) The final layer of representation I discuss is the “aboutness” of words and sentences. So here, I’ll be stepping outside the head to consider the representational features of a very special class of human artefacts. This layer of representation consists in blasts of sound, bodily movements or marks on paper which express mental states, as for example, asserting “grass is green” expresses a belief that grass is green.  It can be analyzed by analyzing the notion of a sentence “expressing” an attitude and, say I, this is a matter of what conventional regularities relate sentences to thoughts in the linguistic community in question. We can understand how this kind of representation can exist in a fundamentally physical world, so long as we have an independent illuminating grip on conventions and the attitudes expressed and so long as the second layer of representation is available to cash out the appeal therein made to representational mental states.

So that’s the overview from 60,000 feet. The reality is a bit more complex than this simple three-layer structure suggests. There are many more details to be given, loose ends to be tied, puzzles and objections to be sorted through, and applications to be explored. The macro-structure itself may need some qualification, once we’ve worked this through—for example, it may be that for some attitudes and parts of language, the relative priority of layers (2) and (3) will be reversed. There will be time enough to sort through this later, so I won’t say more now.