I have already announced my endorsement of a hybrid overall theory, a theory that combines elements of simulation, projection, and theorizing. This section formulates a number of ways to blend simulation and theorizing elements into a mosaic of mindreading possibilities. We have already seen that, contrary to traditional wisdom, simulation and theory need not compete with one another.
Theorizing might implement simulation, implying that simulating and theo-rizing jointly execute mindreading. Other relationships are also possible.
2.7.1 Implementation
There are two ways whereby theorizing might implement simulation. This is because simulation for mindreading is (arguably) a ‘‘control’’ operation that directs a variety of processes or operations.17When one simulates a decision process, for example, the control operation directs the creation of pretend desires and beliefs and, once these are created, selects the decision-making system as the system into which to feed these pretend desires and beliefs as inputs. So there is a higher-order process—the simulation control process—
and a number of lower-order processes, such as the decision-making process.
Either of these types of processes might be implemented by a tacit theory.
That is, theorizing could implement the control process, could implement the processes directed by the control process, or both. In none of these cases would simulation be threatened by theorizing.
This general idea is anticipated by Stich and Nichols (1992):
There are some theorists—Fodor assures us that he is one—who believe that the practical reasoning system goes about its business by exploiting an internally represented decision theory. If this is right, then we exploit a tacit theory each time we make a decision based on our beliefs and desires. But now if we make predictions about other people’s behavior by taking our own practical reason-ing system off-line, then we also exploit a tacit theory when we make these predictions. Thus, contrary to the [earlier] suggestion. . . off-line simulation
processes and processes exploiting an internally represented theory are not mu-tually exclusive, since some off-line simulation processes may also exploit a tacit theory. (1992: 47, n. 7)
This denial of mutual exclusivity is exactly right and illustrates one way in which simulating might be implemented by theorizing. Another way is for the
‘‘control’’ process of simulation itself to exploit a tacit theory, for example, a theory describing how pretend states are to be selected, how a suitable psychological mechanism is to be chosen, and how the selected pretend states are to be fed into the psychological mechanism.
I do not myself endorse either of these implementation theses. In the case of a decision-making mechanism, it is vastly more plausible to hold that the mech-anism conforms to certain psychological laws but doesn’t represent or otherwise possess them. This parallels the case of rocks, which obey the dynamic laws of physics without representing them. Similarly, a decision-making mechanism makes decisions as a function of the desire and belief inputs it receives, and this function is describable by psychological laws. But the mechanism does not itself describe those laws; it merely instantiates them. Although this view strikes me as eminently more sensible than its rival, the matter cannot be settled without a satisfactory theory of tacit knowledge or representation. As we saw in section 2.3, such a theory is not easy to come by. So all I am saying here is that it isn’t essential to ST’s viability that the theory-implementation story be false. I believe it is false, but I don’t have to defend that view in detail.
2.7.2 Cooperation
If all third-person mindreading used simulation, then even if simulation were implemented by theory, there would be a sense in which pure simulationism would be vindicated: No mindreading would occur without simulation. But suppose that many token mindreading routines combine simulation elements with theorizing elements, where the latter are not simply simulation imple-mentations. Then pure simulationism certainly would not be correct. A hy-brid approach would be called for. I call this scenario ‘‘cooperation,’’ and it seems to me highly probable.
For the sake of concreteness, two plausible examples of cooperation may be sketched. First, theory may be used to select pretend inputs. In a decision-prediction task, an attributor would use theoretical reasoning to infer the target’s initial states (desires and beliefs), for which corresponding pretend states are constructed. The pretend states are then fed into the decision-making mechanism, which outputs a decision. The first step of this sequence features theorizing, whereas the remaining steps feature simulating.
A second example introduces a different pattern of mindreading, probably as common as the pattern of decision-making prediction. In decision prediction,
the target’s initially specified states are presumptive causes of a subsequent effect or outcome, which is to be calculated. The mindreader moves ‘‘forward’’
from the prior evidence events to their effect. Many mental attributions, how-ever, must fit a second pattern, in which a sought-after mental state is the cause of some known (or believed) effects. Here the attributor moves ‘‘backward’’
from evidence states (observed behavior, facial expressions, etc.) to the mental cause of interest. How might the second pattern involve simulation? The dif-ficulty is that psychological mechanisms probably do not run backward, only forward.18 If mechanisms are restricted to forward directionality, how can simulation be employed in an evidence-posterior pattern?
This type of mindreading might be approached via a generate-and-test strategy. The attributor begins with a known effect of a sought-after state, often an observable piece of behavior. He generates one or more hypotheses about the prior mental state or combination of states that might be responsi-ble for this effect. He then ‘‘tests’’ (one or more of) these hypotheses by pre-tending to be in these states, feeding them into an appropriate psychological mechanism, and seeing whether the output matches the observed evidence.
When a match is found (perhaps the first match, or the ‘‘best’’ match), he attributes the hypothesized state or combination of states to the target.
The generate-and-test strategy employs simulation at a crucial juncture but also relies on theorizing. Theorizing seems necessary to generate hypothe-ses about states responsible for the observed effects, hypothehypothe-ses presumably prompted by background information. Thus, pure simulationism is inappli-cable here. The generate-and-test strategy requires cooperation between simulating and theorizing. This is another major reason that a hybrid approach seems compelling.
2.7.3 Independence
A final type of relationship between simulating and theorizing is indepen-dence. This means that some instances of mindreading—possibly entire ca-tegories of mindreading—are executed wholly by simulation or wholly by theorizing. Independence refers to cases in which neither method implements the other or cooperates with the other within a single token of mindreading.
Perhaps certain types of mental states are always mindread wholly by theo-rizing, and other types are always mindread wholly by simulating (plus projecting). Or perhaps certain types of evidence are always exploited via theory, and other types are always exploited via simulation. If either of these scenarios is correct, it provides yet another reason that an overall approach must be a theory-simulation blend.
A reader familiar with the traditional configuration of the ST-TT debate may feel a bit perplexed at this juncture. If simulating and theorizing are compatible, especially via the implementation relationship, what happens to
the old opposition between theorizing and simulating? It seems to evaporate.
True, I still insist on the possibilities of cooperation and independence, in which theorizing and simulating retain their distinctive identities. I am not declaring that simulation ‘‘reduces’’ to theorizing or vice versa. But the mod-erate rapprochement between theorizing and simulating that I admit as a possibility seems to blur the old contrast, and that seems unsettling. What are the new terms of debate?
A helpful way to frame the new debate is in terms of ST versus simulation-neglecting TT. Under these terms of debate, it’s no longer enough for TT to show that theorizing somehow takes place in mindreading; it must also show that this theorizing isn’t merely an implementation of simulation.19Orthodox TT has usually denied or minimized the role of simulation. So it seems fair to reconstruct the debate so that TT has the burden of making good on its neglect of simulation. TT must show that theorizing isn’t merely scaffold-ing for simulational processes. By the same token, proponents of ST (or a simulation-centered hybrid) can no longer earn victory over TT simply by showing that theorizing is not the standard method of mindreading. To gain victory over its rivals, ST must establish the intensive use of simulation as defined by the positive characteristics we have described. The major change in our new delineation of ST is that its defenders are no longer required to demonstrate the absence of theorizing. Demonstrating such an absence has long been regarded as a core burden of ST (avoiding ‘‘collapse’’ into TT).
This is an obscure task, given the opacity of the notion of ‘‘tacit’’ theory. The new terms of the debate free ST from this old, misplaced burden.
If the test of ST is a positive one, however, more must be said about the positive characteristics of simulational mindreading. One point in need of clarification is the connection between our resemblance definition of simulation and the standard ST story about mental pretense, highlighted in figure 2.3. So I end this chapter with an explanation of what I mean by mental pretense and how it fits with the resemblance, or duplication, account of simulation.