Philosophical Foundations of Neuroscience. P. M. S. Hacker
brain, just as the maps of an atlas do for the reader of them. The biologist J. Z. Young writes of the brain having a language of a pictographic kind: ‘What goes on in the brain must provide a faithful representation of events outside it, and the arrangements of the cells in it provide a detailed model of the world. It communicates meanings by topographical analogies.’35 But is there a danger in the metaphorical use of such terms as ‘language’, ‘grammar’, and ‘map’ to describe the properties of the brain? … I cannot believe that any neurophysiologist believes that there is a ghostly cartographer browsing through the cerebral atlas. Nor do I think that the employment of common language words (such as map, representation, code, information and even language) is a conceptual blunder of the kind [imagined]. Such metaphorical imagery is a mixture of empirical description, poetic license and inadequate vocabulary.36
Whether there is any danger in a metaphorical use of words depends on how clear it is that it is merely metaphorical, and on whether the author remembers that that is all it is. Whether neuroscientists’ ascriptions to the brain of attributes that can be applied literally only to an animal as a whole is actually merely metaphorical (metonymical or synecdochical) is very doubtful. Of course, neurophysiologists do not think that there is a ‘ghostly cartographer’ browsing through a cerebral atlas – but they do think that the brain makes use of the maps. According to Young, the brain constructs hypotheses, and it does so on the basis of this ‘topographically organized representation’.37 The moot question is: what inferences do neuroscientists draw from their claim that there are maps or representations in the brain, or from their claim that the brain contains information, or from talk (J. Z. Young’ s talk) of ‘languages of the brain’? These alleged metaphorical uses are so many banana skins in the pathway of their user. He need not step on them and slip, but he probably will.
Blakemore’s confusion
Just how easy it is for confusion to ensue from what is alleged to be harmless metaphor is evident in the paragraph of Blakemore quoted above. For while it may be harmless to talk of ‘maps’ – that is, of mappings of features of the perceptual field on to topographically related groups of cells that are systematically responsive to such features – it is anything but harmless to talk of such ‘maps’ as playing ‘an essential part in the representation and interpretation of the world by the brain, just as the maps of an atlas do for the reader of them’ (our italics). In the first place, it is not clear what sense is to be given to the term ‘interpretation’ in this context. For it is by no means evident what could be meant by the claim that the topographical relations between groups of cells that are systematically related to features of the perceptual field play an essential role in the brain’ s interpreting something. To interpret, literally speaking, is to explain the meaning of something, or to take something that is ambiguous to have one meaning rather than another. But it makes no sense to suppose that the brain explains anything, or that it apprehends something as meaning one thing rather than another. If we look to J. Z. Young to find out what he had in mind, what we find is the claim that it is on the basis of such maps that the brain ‘constructs hypotheses and programs’ – and this only gets us deeper into the morass.
More importantly, whatever sense we can give to Blakemore’ s claim that ‘brain maps’ (which are not actually maps) play an essential part in the brain’ s ‘representation and interpretation of the world’, it cannot be ‘just as the maps of an atlas do for the reader of them’. For a map is a pictorial representation, made in accordance with conventions of mapping and rules of projection. Someone who can read an atlas must know and understand these conventions, and read off, from the maps, the features of what is represented. But the ‘maps’ in the brain are not maps, in this sense, at all. The brain is not akin to the reader of a map, since it cannot be said to know any conventions of representation or methods of projection or to read anything off the topographical arrangement of firing cells in accordance with a set of conventions. For the cells are not arranged in accordance with conventions at all, and the correlation between their firing and features of the perceptual field is not a conventional but a causal one.38
Blakemore’ s suggestion that neuroscientists use metaphorical and figurative language because of the poverty of the English language and lack of adequate concepts is a point which we shall examine later (§17.2).39
Reply to fourth objection (Searle)
Searle indeed drew our attention to an interesting conceptual complexity, which is worth disentangling if one is to avoid his confusions. It is a subtle matter, involving the important distinction between the body a human being is and the body a human being has. A human being is a sentient, living spatio-temporal substance (Homo sapiens) consisting of flesh and bones, with the power of self-movement as well as intellectual powers of reason and will. We also use the idiom of having a body (e.g. one may have a beautiful, lithe, athletic, powerful, aged, frail body), which idiom is used to speak of somatic characteristics of the human being we are.40 Everything true of the body we have is true of the body we are, but not vice versa. If my body is dirty, covered with scratches, and sunburnt, then I am dirty, covered with scratches and sunburnt. But if I am thinking of relativity theory, remembering last year’ s holiday, and wondering what to do, my body – the body I have – is neither thinking, remembering, nor wondering, since these are not somatic properties.
Searle suggested that if ascribing psychological attributes to the brain really were a mereological error, then it would vanish if one ascribed them ‘to the rest of the system’ to which the brain belongs. The ‘rest of the system’, he held, is the body that a human being has. He observed that we do not ascribe psychological attributes to our body. With the striking exception of verbs of sensation (e.g. ‘My body aches//itches//hurts//all over’, as well as ‘You have hurt my foot’) this is correct. We do not say ‘My body perceives, thinks and knows’, nor do we say ‘My body has a pain in its foot’, let alone ‘My body has a pain in my foot’ or ‘You have given my foot a pain’. But the ‘system’ to which the human brain can be said to belong is the human being. The human brain is part of a human being, just as the canine brain is part of a dog. My brain, the brain I have, is as much a part of me – of the living human being that I am – as my legs and arms are parts of me.
Human beings are (actually or potentially) persons, that is, they are intelligent, language-using animals that are self-conscious, possess knowledge of good and evil, are free and responsible for their deeds and have rights and duties. To be a person is, roughly speaking, to possess such abilities as qualify one for the status of a moral agent. It is striking that we would probably not say that the brain is part of the person, but rather that it is a part of the human being who is the person or that it is part of the person’ s body. To have a brain, one might say, is a somatic feature of a human being. Interestingly, we would not hesitate to say that Jack’ s brain is part of Jack, part of this human being, just as his arms and legs are parts of Jack. Why this hesitation or reluctance to aver that the brain is a part of a person? Perhaps because ‘person’ is, as Locke stressed, a ‘forensic term’, but not a substance-name like ‘cat’, ‘dog’ and ‘human being’. So, if we use the term ‘person’ in such contexts as this, we indicate thereby that we are concerned primarily with human beings qua possessors of those characteristics that render them persons, in relative disregard of corporeal characteristics. Perhaps this analogy will help: Paris is a part of France, France belongs to the European Union, but Paris does not. That does not prevent Paris from being a part of France. So too, Jack’ s being a person does not prevent his brain being a part of him.
Reply to fifth objection (Dennett) that there is no mereological fallacy, but rather a confusion between mechanical processes of the brain and non-mechanical mental processes
The mereological fallacy of illicitly attributing properties of wholes to their constituent parts has nothing to do with the distinction (or distinctions) between mechanical and non-mechanical processes. It is the bracket clock as a whole that keeps time, not its fusée, although the process of keeping time is