A Materialist Theory of the Mind

"It’s a classic work, which helped to establish the foundations for contemporary philosophy of mind. It’s a sort of bridge between the armchair philosophy of mind you mentioned (Armstrong studied at Oxford in the early 1950s) and the later more scientifically oriented approach I was talking about, and it sets the scene for a lot of what was to follow over the next quarter of a century . (In the 1993 reprint Armstrong added a preface discussing what he thought he’d missed in the original; it’s not a huge amount.) The book also functions as a good introduction for anyone new to philosophy of mind because Armstrong begins with a survey of different views of the metaphysics of mind, including Cartesian dualism – the idea that we have an immaterial soul that is completely distinct from the body – and other important theories, such as behaviourism, the view associated with Gilbert Ryle. Behaviourism is itself a materialist view, in that it denies that minds are immaterial things. In fact, behaviourists deny that minds are things at all. They argue that when we talk about a person’s mind or mental state we’re not talking about a thing inside the person, but about how the person is disposed to behave. So, for example, to have a sudden pain in your knee is to become disposed to wince, cry out, rub your knee, complain, and so on. Or (to take an example Ryle himself uses) to believe that the ice on a pond is thin is be disposed to warn people about the ice, be careful when skating on the ice, and so on – the nature of actions depending on the circumstances. Armstrong is quite sympathetic to behaviourism and he explains its advantages over Cartesian dualism and other views. He sees his own view as a natural step on from behaviourism. He agrees with Ryle that there is a very close connection between being in a certain mental state and being disposed to behave in certain ways, but instead of saying that the mental state is the disposition to display a certain pattern of behaviour, he says it is the brain state that causes us to display that pattern of behaviour. A pain in the knee is the brain state that tends to cause wincing, crying out, knee rubbing, and so on. The belief that the ice is thin is the brain state that tends to cause giving warnings, skating with care, and so on. The idea is that there is some specific brain state (the activation of a certain bunch of nerve fibres) that tends to produce the relevant cluster of actions, and that this brain state is the mental state – the pain or the belief, or whatever. Armstrong’s slogan is that mental states are ‘states of the person that are apt for the bringing about of behaviour of a certain sort’. So the mind turns out to be the same thing as the brain or the central nervous system. Armstrong calls this view central-state theory . It’s also known as the mind-brain identity theory or central-state materialism . Yes, Australian philosophers played a central role in developing the mind-brain identity theory – not only Armstrong, but also J J C Smart and U T Place (Smart and Place were both British, but Smart moved to Australia and Place lectured there for some years). Indeed, identity theory was sometimes referred to as Australian materialism – sometimes with the (unwarranted) implication that it was an unsophisticated view. Australia has continued to produce important philosophers of mind – Frank Jackson and David Chalmers, for example, though those two have been critical of materialism. It’s in three parts. In the first part of the book, Armstrong makes a general case for the view that mental states are brain states (the central-state theory). He sets out the view’s advantages – for example, in explaining what distinguishes one mind from another, how minds interact with bodies, and how minds come into being. Then in the second part – which takes up most of the book – he shows how this view could be true, how mental states could be nothing more than brain states. He surveys a wide range of different mental states and processes and argues that they can all be analysed in causal terms – in terms of the behaviour they tend to cause, and also, in some cases, the things that cause them. So when we talk about someone willing, or believing, or perceiving, or whatever, we can translate that into talk about causal processes, about there being an internal state that was caused in a certain way and tends to have certain effects. These analyses are very detailed and often illuminating, and they go a long way towards demystifying the mind. Armstrong shows how mental phenomena that may initially seem mysterious and inexplicable can be naturally understood as complex but unmysterious causal processes. Well, the causal analysis shows that mental states are just states that have certain causes and effects – that play a certain causal role . That doesn’t establish that they are brain states. They could be states of an immaterial soul. But it shows that they could be brain states. And putting that together with the general case for mind-brain identity made in the first part of the book, it’s reasonable to conclude that they are in fact brain states. There’s a short third part to the book in which Armstrong argues that there is no reason to think that brain states couldn’t play the right causal roles, and therefore concludes that central-state theory is true."