Hurley has addressed the challenging problem of getting from the subpersonal level to the personal – from casual processes to knowledge. We agree with her starting point being in action and her use of layers, but we see two types of problem with her approach.
One is the error of omission, in that Hurley endorses positions that have been extensively critiqued. She buys into a reconciliation of theory theory (TT) and simulation theory (ST), and thereby inherits the problems inherent in both. We, and others, have identified fundamental flaws in TT and ST (e.g., Carpendale & Lewis Reference Carpendale and Lewis2004; Reference Carpendale and Lewis2006), but they are still taken for granted and seem to be immune to criticism.
Second, in attempting to forge links between layers, Hurley makes a series of errors of commission. The layers are bridged by jumps that fudge the distinction between information and knowledge. At the level of causal processes we can talk about information in one sense of the word, such as a digital camera recording a scene. The camera contains information, but this is very different from the knowledge that a person might acquire through observing the same scene. It is knowledge that Hurley's model has yet to account for. And this is the start of her problems.
There are consequences of both types of error. Central to the transition between layers, for Hurley, is involved the miraculous shift from copying or “mirroring” to “action understanding.” The oft-repeated mantra is: “I perceive your action by means that engage my capacity for similar action, enabling me to copy or understand your action” (sect. 4.1.2, para. 4). That is, I see an action, I have a tendency to mirror it, and through this process I understand the action. We will set aside the problems of how mirror systems develop and whether they should be thought of as a source or an outcome of development, and instead point out that in most circumstances this would not work. For example, I see pointing, and I have a tendency to imitate it; that is, a tendency for my arm and index finger to extend. But this would not help in understanding the action.
Consider the following examples. At a picnic on the beach, my (Carpendale's) wife looked at me and pointed to a friend's bag. It was clear that she wanted to direct my attention, but why did she want me to look at the bag? Was there something special about it? Did she want me to do something with it, get something out of it? Give it to her? How was I to understand this gesture? If I copied, or mirrored, this arm movement, it would not help in understanding her action. A little more information about the situation might help. We were picking things up, preparing to walk further down the beach. Yet still I failed to understand her, although by now readers may be thinking of possible meanings. In fact, I had to ask her what she meant. It turned out that she knew that the bag was heavy and she wanted me to carry it for our friend. Given shared experience in helping others, it is, in fact, reasonable to expect that this gesture might be understood. This need for experience in shared routines in order to understand gestures is clarified by considering research with chimpanzees.
Although chimpanzees can follow an experimenter's gaze direction and pointing gestures and end up looking at a bucket where food is located, they do not understand the gesture (Hare & Tomasello Reference Hare and Tomasello2004). Chimpanzees do not understand that the experimenter is trying to tell them where the food is located because they have never experienced such a form of cooperative activity with others; they have never had a conspecific indicate food for them. However, they do have plenty of experience with competition, and if the event is transformed into a competitive encounter – if they know they are competing for food with the experimenter – then if they see the experimenter reaching for a bucket they immediately know where the food is. So what is needed in addition to the action in order to understand that action? The animal needs some experience with that form of interaction. No amount of mirroring or copying, even if it was “offline copying,” would help the chimpanzee.
For Hurley, action understanding is a foundation for later “mindreading,” which she distinguishes from “mere behavior prediction” (sect. 2.3.3, para. 4); that is, “discovering another player's intention, not simply predicting his behavior” (sect. 2.3.3, para. 7). But what else is there to predict other than people's action, broadly conceived to include verbal action? The very term “mindreading” conflicts with her foundation in action, and to do this Hurley buys into the mysticism of contemporary theory and its dualist assumption that new substance is added in addition to action. She later acknowledges that mindreading has to be based on observation of behavior, but, if so, what is the means by which the transition to it occurs? We need an account of social understanding that does not rely upon the crumbling foundations of behaviorism or dualism, both of which split intentional activity into two parts.
Our point here is that nothing about the physical movement, whether it is mirrored or not, would help in understanding the action of pointing in various situations. Instead, what is needed is experience in similar sorts of routines. This is missing from Hurley's model. She does write about various forms of “action understanding,” so perhaps she has a loophole, and these might be graded in terms of their complexity. Her intuition about understanding others' actions might work in simpler situations such as seeing another reach to grasp something. But it might work in such cases only because of the shared experience in this form of action. This is overlooked in her model and then she encounters problems with the slightly more complex cases that we discuss. What are the simpler forms of action understanding and how can the transition from simpler to more complex forms be accounted for in Hurley's model? These are crucial questions. Although layering is a useful metaphor to help us envisage these questions, Hurley's model does not help bridge these layers.
