The Architecture of the Mind

"To some extent. It’s a work of substantive psychological theorising. Carruthers makes the case for the thesis of massive modularity – the view that the mind is composed of numerous separate subsystems, or modules, each of which has a specialised function. This view has been popular with people working in evolutionary psychology, since it explains how the human mind could have developed from simpler precursors by adding or repurposing specific modules. Carruthers argues that this view offers the best explanation of a host of experimental data. First, it’s an excellent example of what philosophy can contribute to psychology. Carruthers surveys a huge range of scientific work from across the cognitive sciences and fits it together into a big picture. As I said, this is something experimental psychologists are often wary of doing, because it means going beyond their own particular area of expertise. Second, the massive modularity thesis is an important one, and Carruthers’s version of it is the most detailed and persuasive one I’ve met. Third, because of the way Carruthers argues for his views, drawing on masses of empirical data from neuroscience, cognitive psychology, social psychology, it is a very informative work. Even if you completely disagree with Carruthers’s conclusions, you will learn a vast amount from this book. This notion of a mental module was made famous by Jerry Fodor in his 1983 book, The Modularity of Mind . As I said, a module is a specialist system for performing some specific task – say, for processing visual information. Fodor had a strict conception of what a module was. In particular, he thought of modules as encapsulated – they couldn’t draw on information from other cognitive systems, except for certain specific inputs. Fodor thought that sensory processes were modular in this way, but he denied that central, conceptual processes were – processes of belief formation, reasoning, decision making and so on. Indeed, he couldn’t see how these processes could possibly be modular, since in order to make judgements and decisions we need to draw on information from a variety of sources. Obviously, if the mind is massively modular, then it can’t be so in Fodor’s sense, and Carruthers proposes a looser definition which, among other things, drops the claim that modules can’t share information. He argues that evolution equipped animals with numerous modules like this, each dedicated to a specific task that was important for survival. There are suites of these modules, he thinks: learning modules, for forming beliefs about direction, time, number, food availability, social relations, and other topics; motivational modules, for generating different kinds of desire, emotion, and social motivation; memory modules for storing different kinds of information, and so on. He argues that the human mind has these modules too, together with various additional ones, including a language module and modules for reasoning about people’s minds, living things, physical objects, and social norms. Carruthers has several arguments. One is evolutionary. This is how complex systems evolve. Nature builds them bit by bit from simpler components, which can be modified without disrupting the whole system. This is true of genes, cells, organs, and whole organisms, and we should expect it to be true of minds too. Another argument is from animals. Carruthers argues that the minds of non-human animals are modular, and since our minds evolved from such minds, they will have retained their basic modular structure, with various new modules added on. A third argument turns on considerations of computability. Carruthers argues that the mind is a computational system; it works by manipulating symbols in something like a language of thought. And for these computations to be tractable, they can’t be done by a general system that draws on all potentially relevant information. It would just take too long. Instead, there must be specialised computational systems – modules – that each access only a limited amount of the information available in the wider system. This doesn’t mean that the modules can’t share information, just that they don’t share much of it. Of course, these are arguments only for the general principle of massive modularity; the arguments for the existence of the specific modules come later in the book. This is the big challenge for the massive modularity view. How can a collection of specialist modules support flexible, creative, and scientific thinking of the kind we are capable of? We can think about things that are not of immediate practical importance, we can combine concepts from different domains, and we learn to think in new and creative ways. How can we do this if our minds are modular? Carruthers devotes a lot of the book to answering this challenge in its various forms. It’s a long story, but the core idea is that these abilities involve co-opting systems that originally evolved for other purposes. Language plays a crucial role in the story, since it can combine outputs from different modules, and Carruthers argues that flexible and creative thinking involves rehearsing utterances and other actions in imagination, using mechanisms that originally developed for guiding action. (You’ll notice that this picks up a theme from Dennett and Millikan – that language is key to the distinctive powers of the human mind.) Carruthers thinks that we are conscious of things we mentally rehearse, so this is at the same time an account of the nature of conscious thought. It’s a very attractive account in its own right – another reason to read the book – and you might endorse even if you are sceptical of the modular picture that goes with it. Carruthers has developed his account of conscious thought further in his most recent book The Centred Mind . The modules might not be evident from the anatomy. Carruthers isn’t claiming that each module is localised to a specific brain region. A module might be spread out across several regions, as the circulatory system is spread out across the body. But the modular theory should generate many testable predictions. For example, we should find distinctive patterns of response under experimental conditions (say, when a task places heavy demands on one module but not on another), distinctive kinds of breakdown (as when a stroke damages one module but leaves others intact), and distinctive patterns of activation in neuroimaging studies. What Carruthers is doing is setting out a research programme for cognitive science, and it’s only by pursuing the programme that we’ll find out whether it’s a good one. Does the programme lead us to new insights and new discoveries? This is very from far armchair conceptual analysis."