The problem of other minds

Robots are topical. They’re taking jobs previously done by humans. As they become more complex, will they acquire ‘minds’? Or will they simply (?) start to behave as if they have minds? As a first step towards answering this question, we need to forget about robots. Instead, we need to need to look more closely at what we mean by ‘mind’.

Within the Western tradition, mind and body have tended to be seen as radically different types of thing. The body is material and exists objectively in physical space. I can see your body just as you can see mine. The mind is immaterial and exists subjectively in something we might loosely call ‘inner space’. I cannot see your mind, nor can you see mine. The claim which seems to follow from this is that no one can have direct access to any mind other than their own. This claim, in turn, gives rise in philosophy to the so-called problem of other minds: given that I have direct access only to my own mind, how do I know – that is, how can I be sure – that you have a mind too? Perhaps you are an automaton, a robot, that behaves as if it has a mind but does not in fact have one.

The ‘problem of other minds’ would be much more troubling (much more of a problem, in fact) if the sole kind of indirect access we had to other minds was by report. If you were able merely to tell me what you are thinking or feeling, then it’s much more plausible to suppose that you might be lying – not in the sense that you’re really thinking or feeling something else, but in the more radical sense that you don’t have any thoughts or feelings at all. But verbal reporting is by no means the only kind of evidence that we have of (possible) events in other minds. Your non-verbal behaviour (including the way you use your voice) is full of clues as to what you’re thinking or feeling. Indeed, your ‘body language’ can be much more revealing than the spoken word.

It’s easy enough to imagine a robot that has no thoughts or feelings but which claims, by means of spoken words, to have such things. It’s also easy enough to imagine such a robot passing what is called the ‘Turing Test’ (after the great mathematician, Alan Turing, who invented it in a thought experiment) by apparently intelligently answering any questions put to it. But it’s extraordinarily difficult to imagine a robot that has no thoughts and feelings but which suggests their existence by means of behaviour as varied and subtle as human body language; if we came across such an advanced robot, surely we would attribute a mind to it. Of course, this doesn’t ‘solve’ the problem of other minds in a strictly logical sense. But it’s a very good reason to suppose that that problem is misconceived, a kind of philosophical red herring. The problem of other minds arises because we suppose that mind and body are radically different kinds of thing. But what if this isn’t the case? What if ‘mind’ and ‘body’ are really just two different ways of talking about – or different aspects of – the same thing, like two sides of a coin? Or what if our physical and our mental being constitute some kind of continuum? If we assume this to be the case, then the fact of such varied and subtle body language in human beings (and in other animals too) comes as no surprise at all. It’s exactly what we would expect.

There is another, related reason for thinking the ‘problem of other minds’ to be misconceived. Up to now I’ve used the term ‘mind’ in a sense that implies consciousness. But consciousness is a slippery thing. Most basically, if I see a stone, I am conscious of the existence, presence and appearance of that stone. But I can also, simultaneously, be self-aware, aware of my own seeing of the stone. It is only through this self-awareness that I seem to myself to have a mind. I might even say, loosely but still, I think, meaningfully, that ‘I am conscious of being conscious’ of the stone. But it is wholly wrong to think that my own mind can be an object of consciousness to me in the way that a stone can be an object of consciousness to me. Once we realize this – once we realize its full implication – we will understand that a mind is not a thing at all. And once we stop thinking of a mind as a ‘thing,’ albeit an ‘inner thing,’ we will come to realize that minds are after all much more transparent and open to others (through both body language and report) than the ‘problem of other minds’ would have us believe, for there is literally nothing (no thing) that is hidden inside us!