What is the Mind?

It is an amusing exercise to ask graduate students of psychology what ‘the mind’ is. Psychology is of course the science of the mind, and yet they have great difficulty answering the question. I gain the impression from their answers that the more you study psychology the less you know about the mind. They seem to end up believing that it is just a very complicated information- processing device. They forget what it means to be a mind.

Since in a sense the mind is all we are, the question as to what it is warrants a moment’s consideration by us all. Here are some pointers ...

The primary property of the mind must surely be subjectivity. A mind can only be perceived by itself. We all experience the objects around us but each of us can experience only one mind – our own. For this reason philosophers speak of ‘the problem of other minds’. How do we know for sure that other minds really exist? Philosophers make matters more difficult than they need to be. Scientists avoid such ultimate questions; we are satisfied with provisional answers based on the best available evidence. Starting from the indisputable fact that I myself exist (cogito ergo sum) I notice by looking in the mirror that I also exist objectively; that I have a particular anatomical form. I also observe that my subjective experience is inextricably tied to my anatomical form and its behaviour. My anatomical form and behaviour, then, are the same thing as me. From this I am able to reasonably infer that other things which look and behave like me from the outside must feel like me from the inside, even though I cannot get inside them directly. In fact normal people don’t even have to infer things like this; they just know them. They call it empathy.

This leads to a second fundamental criterion of the mind. I am led to assume that things which do not look and behave like me from the outside do not feel the same as me from the inside. For example, although I am ready to assume that there must be some sort of state called ‘being a rock’, I cannot accept that rocks have minds like me. I am only willing to accept that things which look and behave like me have minds like me. But how much must their appearance and behaviour differ from mine before I start to lose confidence that they feel like me? (Many questions about animal rights start from here.) The answer would have to be: so long as we share the same basic physical properties we may be assumed to share the same psychological ones. Things which are physically identical probably are identical. We may call this the anatomical principle. But can we be more precise: which are the crucial bits? If my finger is amputated I am subjectively changed in ways quite different from how I am changed if parts of my brain are removed. On this basis it is possible, by systematic elimination, to identify the exact parts of our anatomy that mediate our mental states. Any creatures that share those parts, then, have minds of some kind. Neurologists call this localization.

So which parts are we talking about? I would say there are two. First are the parts associated with core consciousness. This implies that only things which have consciousness have minds; subjectivity alone, like that of a rock, is not enough. This is not to ignore that consciousness admits of degrees. The most primitive parts of the human brain associated with consciousness are embedded deep within the evolutionarily ancient brainstem in a region called the periacqueductal grey. If this 525 million year old structure, smaller than a jelly bean, is damaged all our consciousness is obliterated; it is also the last bit of the brain to shutdown metabolically when we die. This implies that any creature which possesses such a brain structure is capable of consciousness. All vertebrates do. I am therefore willing, on the anatomical principle, to attribute consciousness to lizards but not to oysters.

However, the mind is more than consciousness. Does your mind disappear when you go to sleep? If it does, where does it go to and how do you get it back again when you wake up? We must also not forget everything that Freud taught us about the unconscious mind, the existence of which has been abundantly confirmed by modern neuroscience. In fact, so much of our mental activity turns out to be unconscious that neuroscientists have begun to ask: why do we need consciousness at all?

That is a topic for another day. For now the point is that there is a second part of the brain that is necessary, on the anatomical principle, before a mind can reasonably be inferred. This is variously called the ‘reward’, ‘incentive salience’, ‘wanting’ or ‘SEEKING’ system. Its anatomical trajectory connects the ventral tegmental area of the brainstem with the nucleus accumbens of the forebrain. Without this structure we are zombies. Its principal function is to generate spontaneous activity, to make us get up and go. It is stimulated by any type of need. It causes exploratory or ‘foraging’ behaviour. (Think of a dog in an open field.) It is what makes the world interesting and meaningful to us. In a word, it gives intentionality to life; it injects ‘aboutness’ into life. Intentional aboutness does not have to be conscious (as Freud showed) but it is a second essential difference between minds and non-minds. It is what differentiates the brain from machines, like computers, and from other organs, like the liver. Livers do not have intentions – they are mindless.

The evolutionary origin of this brain system seems to be a primal fact of life, namely the fact that everything we need, biologically speaking, is ‘out there’ in the world. To be alive is to be in an almost constant state of lack, and the things we lack almost always lie beyond our beloved selves. That is why life is difficult. The intentionality system makes us get on with it.

But for now, at least, we have some ideas about what a mind is – the mind is first and foremost something subjective. It is a state of being. For something to be mental it must also be capable of consciousness, and it must be driven to intentionality. These, the three essential properties of the mind, also make it almost impossible to study experimentally. They make it an embarrassment to science. That is why psychologists prefer to focus on something else.