When considering what it means for something to be about / representational / or directed at something else there are three distinct cases that need to be considered. One is representation as encountered in perception, capturing the sense of what I mean when we say that perception is about objects in the external world. Second is representation in thoughts or ideas, capturing the sense of talking about my ideas, thoughts, and concepts being about something non-mental. Finally we have the case of words, pictures, and other inanimate objects, which we can talk about being about other things.
1. About-ness in Perception
Perception is certainly the easiest case to deal with. For our perception to be about something in the world it must inform us that the world is a certain way. For example if we perceive that there is a dog in front of us our perception is about a dog being in front of us. Of course perception can be about things that don’t actually exist. For example we may misperceive or hallucinate, and in this case perception is misinforming us about the world. Still, what such a perception is about is what it was informing us about, even if such information was wrong. So, even if we perceive that there is a dog in front of us where there actually is none, our perception is still about the dog.
It might seem at first glance that this treatment of about-ness in perception is too vague, since we have defined what perception is about in terms of what it informs a subject about, and what it informs a subject about may vary depending on the subject. This is easily remedied however, simply by defining the content of perception more precisely. We should agree that being exposed to some perception the subject’s internal state is transformed from S-1 into some new state, S-2. We define the content of the perception then as the most likely state of affairs that could have caused a perception that would cause the S-1 to S-2 transition. This is why a hallucination is not about an illusionary dog, because the most likely cause of that perception would have been a real dog. (The exact sense of “most likely” might seem a little vague, but I won’t get into it here.)
Conveniently this more formal definition can also be extended to objects without minds as we commonly understand them. For example, we could use this definition to argue that the spinning of a compass’ needle is about magnetic fields. Such a description fits well with Fred Dretske’s paper “A Recipe for Thought”, in which he argues that the primitive intentionality found in simple objects is the kind of thing that our more complicated intentionality is built out of.
2. About-ness in Thoughts / Ideas
A slightly more difficult case to address is what a thought, idea, or mental image is about. Since we can’t tie such occurrences directly to events in the external world we can’t approach the problem in the same way we did with perception. Simple cases, however, can be built upon the treatment of perception, assuming that you accept, as most do, that our perception comes pre-conceptualized (i.e. when we see a tree we don’t see only a particular image, we see it as a tree). Given that, we can say a particular concept or mental image is about whatever state of affairs in the world is the most likely cause for a perception that would invoke that concept. The concept of “dog” then is about all those things that when perceived we would identify as dogs (but not about illusionary dogs, or other cases of misperception, since remember that given the analysis previously about perception can’t be about an illusion, except possibly in very unusual cases).
Obviously though the content of more complex ideas, such as “the war of 1812” can’t be defined in this way. In these cases I think that the content of such ideas must be defined in terms of the simpler concepts, which the more complex one can be broken up into. For example “the war of 1812” is about a “war” that happened in “1812”, and these concepts in turn must be broken up into simper ones, until we arrive at concepts simple enough to be defined in terms of perceptions, at which point the content of the more complex concept can be pinned down by them. At first glance it may not seem possible to define the content of mathematics in this way, but ultimately I think we can pin down numbers in terms of the cardinality of groups of physical objects. A full exploration of this possibility will have to wait until another time, however.
One response that people may have to this account is that “it doesn’t feel that way”. I agree that when we use a complex concept it doesn’t feel as though there are a number of simpler concepts associated with it that are responsible for the meaning, it simply seems to have a meaning. However I contend that these simpler concepts are there, unconsciously in many cases. After all it is through them that we come to understand more complex concepts initially, so I don’t see it as unreasonable that they should remain there in the background, fixing the meaning.
3. About-ness in Words / Pictures
Finally, we come to the case of words, pictures, and other inanimate representations or depictions. In these cases I would say that what they are about depends on the subject that perceives them, and that any universal or objective intentionality that they are said to possess is only an average we talk about for convenience, much like we talk about “the average man”, and not as something that exists on its own. I have detailed this argument elsewhere though, so I won’t go into more detail here. Given then that we are dealing with only a single subject defining the content it easy, it is identical to the concept (or concepts) that perceiving it invokes in the subject. For example the word “dog” is about dogs because it happens to invoke dog-the-concept in me when I hear it. Words, serving as a way to communicate accurately, usually invoke only a single concept, but paintings and sculptures may invoke more.
It may seem then that I am defending a very radical interpretation of art, such that what it is about depends solely on the viewer, and not on the artist’s intent. It is not my intention to step into the world of art criticism here, and to defend myself I should mention again that when we describe a word or painting as about something we often really mean the “average about-ness”. Thus one could rescue the world of art criticism by defining what art is about to be “average about-ness” or “about-ness to the artist”.
How we actually define what it means for one thing to be about another is an interesting project, but there are two lessons here that are of greater relevance for other philosophical endeavors, especially in the philosophy of mind. One is that what about-ness or intentionality is varies depending on the domain we are studying, there isn’t going to be a single definition that fits, for example, perception and language equally well. Secondly, the about-ness of a particular object of study always depends on factors external to that object, which should prompt us to conclude that, properly speaking, its about-ness or intentionality is not part of that object but rather a useful way of describing it that we can engage in from an outside perspective. (for more on this idea see here)