ABSTRACT
Once upon a time Dennett allowed that his theory of the intentional states was essentially an ‘instrumentalist’ sort of theory (see, originally, Dennett 1971, and strong traces remain scattered through Dennett 1987). That is, whether it was correct or not to attribute intentional states such as beliefs, desires, etc. to any system was entirely a matter of the instrumental success gained by the attribution. If one was better able to predict and explain the system’s behaviour by describing it from the intentional stance, then that was all that was required to ground the truth of the predictive and explanatory intentional state attributions. Within the philosophy of science, there have always been objections to instrumentalist accounts of theorizing. For example, it is not clear whether one can really explain
any phenomenon in terms of entities which have no claim to any sort of ‘existence’ except their explanatory role. This seems perversely backwards: surely, for example, electrons explain things because they exist, it is not that they exist because they explain things, although, of course, it may be that we know that they exist because of how they can explain things (an early form of this sort of objection was raised in Cummins 1982). Nor does it seem quite correct to ground intentional state ascription solely upon the possibility of predictively and explanatorily successful ascription since, for example, it seems possible that such success could be grounded in features of a system irrelevant to, or even blatantly inconsistent with, the actual possession of intentional states let alone states of consciousness (for these sorts of objections see Peacocke 1983, pp. 203 ff. or Block 1978 or, for some interesting remarks on Dennett’s irrealism, Block, 1993, or even, by inference, Searle 1980). From the point of view of explaining consciousness there seems to be a much more serious problem with instrumentalism about intentional states. Among other things, it is the desire for explanatory and predictive success, along with the belief that the ascription of beliefs and desires can yield that success, which drives our ascription of desires and beliefs.1 These are conscious desires and beliefs and their existence does not seem to be merely a matter of the predictive and explanatory success that someone else (or ourselves) would gain by attributing them to us! The worry here is that the instrumentalist view of intentional states in fact presupposes unexplained instances of the things it purports to explain.
