Patricia Churchland

Any mention of the relationship, still poorly understood, between body (or brain) and mind invariably invokes the name of Descartes, who is often thought of as the father of modern philosophy and perhaps of neurophilosophy. Although a native of the heart of France (the region around Tours), Rene Descartes travelled widely, as everyone knows, especially to Holland and Sweden. It should come as no surprise, that the Congress of Neurophilosophy and Alzheimer's Disease was the first in the series of Fondation Ipsen Colloques Medecine et Recherche to be held outside France. The meeting was held in San Diego (California) on January 11, 1991. This venue was chosen for a number of reasons. The University of California San Diego is without doubt one of the most dynamic universities today. A good number of friends of the Fondation Ipsen who have taken part as speakers in previous conferences are based there. Patricia Churchland, whose publications have helped "launch" the term "neurophilosophy", also teaches there. The choice of this particular venue gave us the welcome opportunity of benefiting directly during the conference from the participation of many eminent (including some Nobel Prize-winning) scientists, including biochemists, neuro scientists and "alzheimerologist", psychologists, cognitive science specialists and philosophers.

States of the brain represent states of the world. A puzzle arises when one learns that at least some of the mind/brain’s internal representations, such as a sensation of heat or a sensation of red, do not genuinely resemble the external realities they allegedly represent: the mean kinetic energy of the molecules of the substance felt (temperature) and the mean electromagnetic reflectance profile of the seen object (color). The historical response has been to declare a distinction between objectively real properties, such as shape motion and mass, and merely subjective properties, such as heat, color and smell. This hypothesis leads to trouble. A challenge for cognitive neurobiology is to characterize, in suitably general terms, the nature of the relationship between brain models and the world modeled. We favor the hypothesis that brains develop high-dimensional maps whose internal relations correspond in varying degrees of fidelity to the enduring causal structure of the world. From this perspective, the basic epistemological relation is not “single-percept to single- external-feature” but rather “background-brain-maps to causal-domain-portrayed.

The explanation of a child's discriminate responses to his environment turns on ascribing to the child a perceptual discrimination which counts certain things as more similar to one another than to some other thing. As Quine forcefully puts it:If an individual is to learn at all, differences in degree of similarity must be implicit in his learning pattern. Otherwise any response, if reinforced, would be conditioned equally and indiscriminately to any and every future episode, all these being equally similar.Now for those determined to cleave to behaviourist canons, the problem is to use ‘perceptual similarity’ in explaining the subject's discriminating responses in a way which does not imply the existence of mental states and entities. What this really means is that the behaviourist must reconstruct the notion of ‘perceptual similarity', purifying it of its mentalistic dimension. So long as physicalism is a reasonable position, and while we are awaiting and abetting the neurophysiological millennium, the behaviourist's project is of significant moment. Now in Word and Object Quine does not seriously attempt to provide behavioural criteria for a subject's perceiving similarities, and he provisionally permits himself the mentalistic idiom he avows finally to eschew.

Beginning with Thomas Nagel, various philosophers have propsed setting conscious experience apart from all other problems of the mind as ‘the most difficult problem’. When critically examined, the basis for this proposal reveals itself to be unconvincing and counter-productive. Use of our current ignorance as a premise to determine what we can never discover is one common logical flaw. Use of ‘I-cannot-imagine’ arguments is a related flaw. When not much is known about a domain of phenomena, our inability to imagine a mechanism is a rather uninteresting psychological fact about us, not an interesting metaphysical fact about the world. Rather than worrying too much about the meta-problem of whether or not consciousness is uniquely hard, I propose we get on with the task of seeing how far we get when we address neurobiologically the problems of mental phenomena.

Anydomainofscientificresearchhasitssustainingorthodoxy. Thatis, research on a problem, whether in astronomy, physics, or biology, is con- ducted against a backdrop of broadly shared assumptions. It is these as- sumptionsthatguideinquiryandprovidethecanonofwhatisreasonable-- of what "makes sense." And it is these shared assumptions that constitute a framework for the interpretation of research results. Research on the problem of how we see is likewise sustained by broadly shared assump- tions, where the current orthodoxy embraces the very general idea that the business of the visual system is to create a detailed replica of the visual world, and that it accomplishes its business via hierarchical organization and by operatingessentiallyindependently of other sensorymodalitiesas well as independently of previous learning, goals, motor planning, and motor execution.

Philosophy, in its traditional guise, addresses questions where experimental science has not yet nailed down plausible explanatory theories. Thus, the ancient Greeks pondered the nature of life, the sun, and tides, but also how we learn and make decisions. The history of science can be seen as a gradual process whereby speculative philosophy cedes intellectual space to increasingly wellgrounded experimental disciplines—first astronomy, but followed by physics, chemistry, geology, biology, archaeology, and more recently, ethology, psychology, and neuroscience. Science now encompasses plausible theories in many domains, including large-scale theories about the cosmos, life, matter, and energy. The mind’s turn has now come. The classical ‘‘mind’’ questions center on free will, the self, consciousness, how thoughts can have meaning and ‘‘aboutness,’’ and how we learn and use knowledge. All these matters interlace with questions about morality: where values come from, the roles of reason and emotion in choice, and the wherefore of responsibility and punishment. The vintage mind/body problem is a legacy of Descartes: if the mind is a completely nonphysical substance, as he thought, how can it interact causally with the physical brain? Since the weight of evidence indicates that mental processes actually are processes of the brain, Descartes’ problem has disappeared. The classical mind/ body problem has been replaced with a range of questions: what brain mechanisms explain learning, decision making, self-deception, and so on. The replacement for ‘‘the mind-body problem’’ is not a single problem; it is the vast research program of cognitive neuroscience. The dominant methodology of philosophy of mind and morals in the twentieth..

What is morality? Where does it come from? And why do most of us heed its call most of the time? In Braintrust, neurophilosophy pioneer Patricia Churchland argues that morality originates in the biology of the brain. She describes the "neurobiological platform of bonding" that, modified by evolutionary pressures and cultural values, has led to human styles of moral behavior. The result is a provocative genealogy of morals that asks us to reevaluate the priority given to religion, absolute rules, and pure reason in accounting for the basis of morality. Moral values, Churchland argues, are rooted in a behavior common to all mammals--the caring for offspring. The evolved structure, processes, and chemistry of the brain incline humans to strive not only for self-preservation but for the well-being of allied selves--first offspring, then mates, kin, and so on, in wider and wider "caring" circles. Separation and exclusion cause pain, and the company of loved ones causes pleasure; responding to feelings of social pain and pleasure, brains adjust their circuitry to local customs. In this way, caring is apportioned, conscience molded, and moral intuitions instilled. A key part of the story is oxytocin, an ancient body-and-brain molecule that, by decreasing the stress response, allows humans to develop the trust in one another necessary for the development of close-knit ties, social institutions, and morality. A major new account of what really makes us moral, Braintrust challenges us to reconsider the origins of some of our most cherished values.