As the previous shows, the development of neuroscientific tools for investigating real-time brain functioning brings interesting new dimensions to the study of mind. Questions about the relation of mental states to brain states, not least in respect of subjectivity, consciousness and representation, have been central to the philosophy of mind ever since dualism and non-materialist monisms (various idealisms and ‘neutral monism’) were rejected as serious possibilities. But a raft of further questions – about morality, intention, free will, selfhood, rationality, and philosophical aspects of learning, memory and emotion – have also become amenable to investigation with the greater empirical depth offered by functional magnetic resonance imaging (fMRI).
Accordingly we have a promising combination of neuroscience, psychology and philosophy giving rise to a new field of enquiry with a new name: neurophilosophy. The armchair speculations of traditional philosophical enquiry here yield place to something with a more solid basis and some surprising and suggestive findings already to hand. Even before fMRI studies on decision and volition began to suggest that these are pre-conscious processes, we knew that people whose brain hemispheres had been separated by commissurotomy seemed to have two sometimes competing centres of selfhood; and studies of brain chemistry have provided insights into the nature of mental disturbance, emotion and social bonding.
It is however not to be either sceptical or critical of this project to say that a sense of proportion has to be kept regarding its philosophical promise. For when one thinks about persons, their characters, what they know and believe, the frameworks of concepts that organise their view of the world and their attitudes and responses to it, and the way they give weight to competing reasons for action, the neurophilosophical approach is only part of the story, because in principle it cannot be the whole story. The reason is given in the previous essay: minds are more than brains, not in the sense of being some sort of ghostly stuff, but in the sense of being the result of the brain’s interactions and relationships with other minds and the surrounding world.
In other words minds have to be understood ‘broadly’ as opposed to ‘narrowly’, in the same sense that we speak of ‘broad content’ and ‘narrow content’ in relation to mental content generally, as when we say that individuating referential thoughts necessarily involves mention of the referents of the thoughts; thus, to individuate the thought of a chair from the thought of a book necessitates reference to the physical chair and the physical book outside the thinker’s head.
In saying that the character and content of one’s mind is the result of its interaction with its social and physical setting, one is saying that any individual mind is accordingly the product of a community of minds and of input from the world. It develops by continuous feedback in interaction with parents, teachers, the community and the physical environment. Therefore to identify what a person knows and believes, and to describe how he thinks, is to see him as a node in a complex of relationships with other minds and a manifold of accompanying external stimuli. The point might illustratively be put by saying that a mind is the product of many brains in interaction; that externally caused excitations – many of them from other brains – of some subset of sensory surfaces (fingertip dendrites, rods and cones, taste buds, ear drums) are necessary conditions for mental life, to which ineliminable reference must be made in explaining mental content. In short, mind is brain plugged into two kinds of environment, social and physical, and a brain not thus plugged in is not the seat of a mind.
These considerations do not seem to have been given full weight even in the preliminary indications that fMRI gives us about the nature of volition, decision, the place of emotion in reasoning, and like matters of philosophical significance. For example: experiments which suggest that decisions are reached some time (split seconds are aeons in neurological terms) before a subject is aware of having made a decision, take the form of choosing which button to press after receiving a given stimulus. Such decisions are a far cry from deciding where to invest one’s savings or whether to accept a certain job offer. Likewise, the suggestion that moral responses are hard-wired and amygdala-based fails to take into account the way moral attitudes change in individuals and societies over time and as a result of discussion and information.
Again: this is not to call neuropsychology and neurophilosophy into question; it is merely a reminder that questions about mind are not exhaustible by investigation of the brain; there is here still work for philosophy, without a prefixed ‘neuro’, to do.