The Connected Mind
Massive modularity is the order of the day. The mind, like the body, is made up of a large number of separate mental organs (faculties, systems). Here is a typical list: the five senses, memory (several kinds), the moral faculty, the mathematical faculty, the theory of mind faculty, the commonsense physics faculty, the language capacity, the will (motor control), the emotions, the conscious mind and the unconscious mind, facial recognition, sexual competence and performance. The picture is of an array of distinct modules that specialize in certain tasks or competences, each with a characteristic structure and mode of operation, rather like the distinctly individuated organs of the body; the mind is not an undifferentiated blob or a tabula rasa or an indefinitely plastic potentiality with no discrete components or subdivisions. The body is made up of a great many autonomous organs each dedicated to a certain function, each with a distinct type of cellular composition and mode of operation, all contained in a single envelope; the mind is viewed as similarly divided and segregated into heterogeneous units, all comprehended under the broad label “mind”. Correspondingly, the brain is also conceived as modular, with anatomically distinct areas dedicated to particular mental functions; it is nothing like porridge. In each aspect the organism, whether human or animal, is viewed as a collection of separate elements that together add up to a whole bearing a simple name: “body”, “mind”, “brain”. The organism is a feat of modular engineering through and through, no doubt formed by the demands of evolution, the mind as well as the body.
But it is not an unconnected collection: the parts interact and interface with each other. This is as much an aspect of the mind’s nature as its individual components. It can be studied in its own right. This is a large subject that has only just begun. I am concerned here to articulate some general principles and distinctions. I begin with Fodor’s celebrated discussion of the modularity of the senses: the idea that vision (say) is an “encapsulated” system incapable of modification or supervision by the cognitive components of the mind, as is evidenced by the persistence of illusion under conditions of cognitive correction. You will keep on seeing that stick in water as bent even when you know perfectly well that it is straight. Your beliefs are powerless to bring about any alteration in the deliverances of your senses, no matter how you might try to change how you see things. This shows, according to Fodor, that the senses are modular and exist as separate systems in the overall economy of the mind. Of course, the senses are also modular (encapsulated) with respect to each other as well as the “central system” of rational thought: the fact that you feel the stick to be straight with your hands has no power to alter the way it is visually perceived. In general, the senses have no power to govern the operations of each other: what you see doesn’t affect what you hear, what you smell doesn’t determine what you feel. The senses are certainly coordinated, but they don’t penetrate each other’s domains (synesthesia is the closest thing to that). They are self-governed, refusing to heed with their neighbors assert. They are as separate as the bodily organs that serve them. We might say that they form the unconnected mind—as unconnected as the lungs and kidneys or the stomach and the feet. Similarly, bodily sensations are impervious to outside influence: you can’t stop feeling pain simply because you want to or because your intellect tells you there is nothing to worry about. Nor does the sinner stop feeling pleasure because his conscience tells him it is wrong (the sexual module is notoriously impervious to the moral module, and likewise for the gustatory module and the prudential module). There is clearly a good deal of encapsulation in the human mind, as each part of it blithely goes about its specific business. It is not all harmony and concord. It is as if the parts have a will of their own.
But encapsulation is not the general rule; in fact, it is more the exception. Consider memory: memory is open to all-comers, quite promiscuous in what it will allow in. Anything from the senses, thoughts, feelings, acts of imagination, passing desires, other acts of memory: you can remember pretty much anything you can be conscious of (and maybe more than that). Memory is a module that is receptive to every other module, allowing itself to be ruled and structured by what happens outside of it. It is like an organ of the body that takes input from every other organ. Memory is maximally un-encapsulated, hyper-connected: “Only connect” is its invariable motto. Thought is quite similar: Fodor never claimed that thought is encapsulated with respect to the senses—that would be clearly false. What you think is obviously responsive to what you experience perceptually or else empirical knowledge would be impossible. What you believe is obviously affected by what you see, hear, etc. Not everything you think is controlled by your senses—not if there is such a thing as a priori knowledge—but in general thought is not closed to outside influence from the organs of sense. We can perhaps imagine that it could be: there might be a pathological condition in which thought becomes closed off from perception, so that a person’s beliefs are never shaped by what he or she senses. But that is not the wiring-diagram of the normal human and animal mind: the lines are always open to what the senses have to report. Here the modules are different but they are systematically connected (at least in one direction).
Emotion and thought provide an interesting case. There is clearly an interaction between emotion and thought that cuts both ways: emotions can influence thought (even “color” thought) and thought can influence emotion. The connection might be seen as adaptive: it is good for emotion to be shaped by thought so as to enable it to be more fine-grained and rational; and it is good for emotion to influence thought because of its motivational force (emotion can proverbially concentrate the mind). So far, so platitudinous: but the example suggests a useful general distinction between types of intra-mental (but cross-modular) connection, namely that between causal and constitutive connection. It is one thing for causal connections to exist between distinct modules, but it is another thing for the connections to determine the very nature of what belongs internally to the connected modules. It seems true to say that emotions can have their nature fixed by the thoughts that influence them; that emotion has to involve those thoughts. Here cognition and emotion are inseparable. For instance, the thoughts one has about a loved individual are integral to the emotion of love that one feels toward that individual. This is not merely a causal connection but a constitutive one. In view of this constitutive connection, we can reasonably speak of a kind of intra-mental “externalism”: emotions (some of them anyway) have their nature fixed by factors external to the module proper to them; or better, the two modules coalesce at this point. If we consider the cognitive faculty as existing in the “environment” of the affective faculty, then we can say that the latter has its content fixed by something external to it—though that something becomes internal to emotions themselves. The connections are not merely extrinsic but intrinsic—they determine the very nature of emotion. If there were no such connection, the emotions available to a subject would be limited in a way that are not when there is such a connection. On Twin Mind-Earth different thoughts coexist with the same affective module and the result is a different set of emotions: if you vary the thoughts, you vary the emotions. Thought content penetrates emotional content; the psychological “environment” contributes to fixing the inner form of a given mental module. Here we have not just connection between one module and another but annexation, appropriation, penetration. One type of mental state bleeds into another, suffusing it. According to standard externalism, the mind and the environment are not just causally connected but also constitutively enmeshed; and the same kind of relation can bind mental modules to each other. So separation of modules is consistent with constitutive connection. The mind may be an array of separate systems but those systems can saturate each other, shaping their content. We might call this “internal externalism”.
Language affords another example of overlap and interpenetration. The language capacity is best viewed as an internal system that has become hooked up to a sensory-motor system, generally vocal speech (but also sign language in some cases). The two systems interface and cooperate but they are not to be identified: one could exist without the other. Double dissociation is possible, as when a creature can make vocal sounds but not speak a language, or possesses an inner language but has no means of expressing it publicly. But when a creature has a normal vocal language that faculty is an inextricable combination of one module and another: the inner language faculty becomes linked to an outer sensory-motor system and the outer system comes to embody the inner faculty. The two are joined together, even though strictly they are separate mental systems capable of dissociation. Normal human language use is a phenomenon of connection not of the connected things considered separately. Thus sounds come to express meanings and meanings get expressed in sounds. Without the ability to connect the distinct modules the human organism would be incapable of vocal speech. The connections are as vital as the things connected. Evolution can produce modes of connection as much as it can produce the things that are connected; and that is apparently what happened when human speech evolved from the joining of a sensory-motor system and an internal linguistic system.
So we have three types of relation between separate compartments of the mind. First, we have encapsulation in which no pathways exist between one compartment and another—no influence from one part of the mind to another. Here we have what might be called “the unconnected mind” (Fodor’s encapsulation). Second, we have causal pathways that allow for what happens in one part to be affected by what happens in another part, as with conscious events affecting memory and the influence of perception on thought. Third, we have connections that amount to contributions, in which one part of the mind actually shapes another part: here there is a new synthesis that resembles traditional externalism (only now it’s an internal externalism). Modularity can obtain in all three situations, though it is most conspicuous in the first kind of case. What I would emphasize is that the connections are as important as the elements combined: the mind is a connected ensemble of separate modules. Those connections are as worthy of study as the connected elements. Psychology is really the science of the constituent parts of the mind and of their modes of connection: modular connectedness (compare physiology). First it isolates and describes the parts; then it studies their inter-connections.
 I am not intending to endorse traditional externalism, which comes in several forms, some more plausible than others; I am merely pointing to an analogy in order to bring out the way components of the mind can interpenetrate. Once the disunity of the mind is acknowledged it is natural to ask whether the components enjoy constitutive connections with each other, and it appears that in some cases they do. Faculty psychology is thus consistent with inter-faculty crossover.
 The inter-module connections can be as innate as the modules themselves, as much the product of evolution. This is presumably true for the connection between the internal language faculty and the sensory-motor system that typically expresses it in acts of human communication.