Consciousness and the Problem of Other Minds

 

Presentation to the World Congress of Philosophy, July 30 – August 5 2008, Seoul

  John O’Dea

The University of Tokyo

 

1. Introduction

What do we believe when we believe that others are conscious, and why?  When are those beliefs justified?  Attempts to answer these questions within the analytic tradition have focussed on the idea that we arrive at a conception of mentality from some kind of self-awareness, and then attribute mentality under that conception to others through a process of inference, either analogical or abductive. As Ned Block has recently shown, attempts along this line appear to lead to intractable problems for a general theory of consciousness.  On the other hand, key philosophers from the Phenomenological tradition, notably Husserl and Merleau-Ponty, have defended the idea that our awareness of others is not inferential at all, but rather is an inescapable part of our experience. If these philosophers are right, it might be possible to avoid at least one roadblock to a general theory of consciousness.  In this paper, I will argue that recent findings in social neuroscience are relevant to this debate, and that in those findings we find powerful reasons for preferring the non-inferential approach to other minds.  

 

2. Other Minds and the Problem of Consciousness

Ned Block[1] argues that a general theory of consciousness is currently out of our reach because we have no way of knowing which creatures apart from ourselves are conscious.  Because we lack criteria for judging when something is or isn’t conscious apart from introspective observation, we don’t have a starting point from which to theorise. He employs the possibility of a creature exactly like us in all everyday behavioural ways but entirely different physically (he uses the example of Commander Data from the Star Trek television series.) Such a creature, he argues, would in the first instance reasonably be judged to be conscious through a kind of analogical inference.  But that inference, he says, would essentially be an inference from the presence of surface similarity to the presence of an underlying similarity (or an inference to a “common material basis” p.38).  When we discover that there is no underlying physical similarity, the inference is undermined, but in a way that leaves the question of the creature’s consciousness entirely open.  Describing this problem as an epistemic version, or aspect, of the famous “Hard Problem” of consciousness (Chalmers 1996), Block writes that

The root of the epistemic problem is that the example of a conscious creature on which the science of consciousness is inevitably based is us… But how can science based on us generalise to a creature that doesn’t share our physical properties?  It would seem that a form of physicalism that could embrace other creatures would have to be based on them at least in part in the first place, but that cannot be done unless we already know whether they are conscious. (p.25)

The reason that the science of consciousness is inevitably based on us is that the only known example of consciousness is ourselves and, by extension, creatures exactly like ourselves.  We know about our own case because we are introspectively aware of being conscious, and we can infer that creatures similar enough physically are also conscious.  But beyond that we have no way of telling.

 

3. The Inferential Approach to Other Minds

It seems to me that this particular problem arises only if the inferential approach to the problem of other minds is the right one, and I will argue here that recent neuroscience provides evidence against this approach.  I will suggest that our reason for believing in other minds is much more basic, contrary to the received opinion in the philosophy of mind, and that if this is true then we need to rethink the sorts of properties we are actually attributing to others when we attribute consciousness to them, and therefore we also need to rethink what a theory of consciousness in this sense should be about.

Contemporary thinking on this problem arises from the writings of J.S Mill (1865)[2] in the mid 19^th century.  Mill asked how it is that we know, and why it is that we believe, that the various walking and talking figures around us have experiences and feelings as we do.  He argued that it is by analogical inference; we have many visible similarities to the figures around us, and therefore it is reasonable to suppose invisible similarities as well:

I conclude that other human beings have feelings like me, because, first, they have bodies like me, which I know in my own case to be the antecedent condition of feelings; and because, secondly, they exhibit the acts, and other outward signs, which in my own case I know by experience to be caused by feelings.

Within analytic philosophy there has been considerable discussion about the validity of this inference, which I won’t describe here.  This discussion has centred around the question of what sort of inference could validly lead us to the conclusion that there are other minds.  The prevailing view is that the appropriate inference is an inference to the best explanation: the idea that others have minds is the best explanation of their behaviour.

 

4. Recent Evidence for the Non-inferential Approach to Other Minds:

The Mirror Neuron System

The analogical approach was rejected early by the phenomenologists, not because it was the wrong kind of inference but because, they argued, we never use an inference at all. Merleau-Ponty claimed that in order to see others as experiencing the same sort of things that I experience, I need to see my own body movements as not the causes and results of inner experience but rather as partly constituted by them.  If we can achieve this, then seeing the bodily movements of others as similar to my own bodily movements would be to automatically see them in partly mental terms.  And, of course, Merleau-Ponty spent a lot of time spelling out in detail the ways in which he though we experience our “inner” lives as constitutively embodied, Merleau-Ponty argued[3] that our awareness of others begins in infancy.  Infants are able to mimic adult behaviour before they can know that their bodies are similar to the bodies of the adult.  He claimed that the infant’s proprioceptive awareness of its own body must already contain an anticipation of the other.  The infant is able to see the other’s action in terms that it already understands as the action of another agent—that is to say of an intentional agent.  The infant does not infer the presence of another intentional agent from the sight of behavior similar to its own.  It already sees the behaviour as intentional behaviour.

Recent neuroscientific discoveries lend support to Merleau-Ponty’s claims in this respect, and have shown that infants mimic the facial expressions of others within hours of being born.  Although this mimicking behaviour was long assumed to be a kind of motor reflex, it is currently thought to involve the recently discovered “mirror neuron system”. This system is a set of neurons that were originally discovered in monkeys to be active both in the course of a motor action and in the course of the perception of that same action in others. It is thought that a mirror neuron system is preserved in the human brain[4], and may underpin all social perception and thought.

Behavioural studies have shown[5] that young infants are aware of the difference between “inanimate” objects, even animated ones such as toy robots, and animals, and treat them differently.  They are also aware of the difference between animals, which they want to touch, and other human beings, who they do not try to touch but rather habitually look at as if for approval.

 

4. Recent Evidence for the Non-inferential Approach to Other Minds:

Eye Gaze and the Co-development of Self and Other

Awareness of gaze is important in the phenomenological tradition. According to Sartre, there is something quite special, and certainly non-inferential, about the experience of being looked at.  Being aware of another in this way involves being aware of myself as an object, and this is the only way I could come to be so aware.  My own self-awareness is therefore bound up with my awareness of others.  I do not so much project my introspections outward as feel the mind of another being projected towards me.

Again, recent behavioural studies appear to confirm that Sartre was right to emphasize the importance of gaze in the development of our awareness of both ourselves and others.  From about two months of age, infants become aware of, and very interested in, the direct gaze of others. Importantly, even at this very young age they respond to gazes with what appears to be a limited range of social emotions – most notably, embarrassment and pride[6].  Interestingly, at this point it is only the direct gaze of others that infants seem to be aware of; that is to say when they see another person looking back at their eyes.  Looking at other parts of the body elicits no response.  Over the course of the first year, infants begin to become aware of the gaze of others being directed towards their body, then their actions, and lastly third-person objects.

Until fairly recently, it had been thought that infants can not feel self-conscious until they become aware of having a self, which was established to be around the 18 month mark.  But this relatively sophisticated sense of a continuing “I” may well be the end product of a series of cognitive developments that begin with the child’s first awareness of itself as an object of another’s attention.  Thus the development of our awareness of others and of our awareness of ourselves may be parasitic on one another from the very beginning.

 

6. A Neutral Conception of Mind

Avramides[7] has recently argued, following Wittgenstein and others, that no inference from my possessing a mind begins with introspection, because the minds of others are not the sorts of properties that I can introspect.  Rather than taking my own case – or, indeed, the case of others – as a starting point, we must begin with concepts that are neutral between the first and second person, such as the concept of an action, following Strawson.  These concepts, understood as concepts that are neutral between actions or conception of myself or of others, would be consistent with a growing body of evidence from the neurosciences that has led many leading researchers in the field[8] to suggest that our first awareness of ourselves as agents, or even as subjects of experience, is already an awareness of being situated in a social setting, that is to say among other minds.

To summarize, the accumulated empirical evidence suggests strongly that our awareness of others is cognitively basic and begins no later than our awareness of our own selves.  Moreover, from when we start to be aware of others, there is evidence that this becomes our default mode of thinking. A recent study by Schilbach et al[9] has shown that when the brain is “at rest”, that is, when a person is not engaged in any particular mental task, there is continuous activity in the areas of the brain associated with social thinking. Though it is possible in thought to step back and try to justify our beliefs in other minds, our own brains never give us the chance to take seriously that others don’t have minds.

 

7. Conclusion

What this debate gains from social neuroscience is not direct evidence about what is the right analysis of our concepts of other minds, but rather indirect evidence that whatever that concept is, it is based on our experience of the world as infants, at an age when we are not yet fully aware of ourselves as independent seats of awareness.

If our conception of consciousness is such that we did not acquire it from our own case, then to attribute it to others is not to infer, in Block’s words, an internal similarity from an external similarity.  Block’s harder problem of consciousness, which must arise if that sort of inference is involved in our justified attribution of consciousness to others, dissolves if no such inference is needed.  I have tried here to give some empirical reasons from recent cognitive neuroscience for thinking that our conception of other minds is not the sort of conception that requires an inference from myself to others.

Block argues that a general science of consciousness is impossible because we cannot know the range of creatures that have consciousness.  We cannot know that range because consciousness is something we originally know only through introspection, and which therefore allows us justifiably neither to make nor withhold its attribution to physically very different creatures.  But, as I have argued, the science of consciousness is not based on us because of an inferred connection between a physical appearance and in “internal” mental state, but rather because our conception of mentality does not allow for a sharp distinction between the two.  We see certain actions as conscious actions, and our resulting conception of consciousness applies properly to Commander Data because of the way we perceive him.  The science of consciousness therefore includes him as an instance, just as it excludes inanimate objects.  The harder problem of consciousness as Block defends it arises from a particular view about the nature of our conception of consciousness – one that requires that we infer it in others –and that view is not supported by current neuroscience.