Neurophilosophy and free will VI

Neurophilosophy and free will VI

Introductory remarks Neurophilosophy is a programme that has been intensively studied for the last few decades. It strives towards a unified mind-brain theory in which the mind can be understood as a function of the brain. The reader may be surprised that in this section of the book we also speak about free will. The problem of free will is related to the overall theme of the present publication because it is becoming ever more clear that sensory perception imperatively requires the reference to motor function. It is only possible to verify that the physical effect of the outside world on a selfsustaining system elicits sensory perception, if we can show that the respective system responds to physical affections with reactions that are mostly motor actions but can also be chemicalor neuronal. These reactions have to be interpreted as functional in the service of self preservation of the respective system. Man experiences, at least subjectively, the world as if his/her motor skills were in many ways steered by free will. Because of the close connection of sensory and motor skills it must be assumed, that the human species-specific peculiarities of sensory perception are also affected by the requirements of the species-specific steering strategies of its motor function. Therefore, we decided to make space for the problem of free will in an anthology on sensory perception. The problems that emerge in this context may also 1. be relevant for a number of animal groups where, at the least, indications of similar behavioural steering strategies can be ascertained, e. g. primates or ravens. Neurophilosophy In his contribution on "Neurophilosophy" Gerhard ROTH traces the boundaries of this rather recent discipline. Neurophilosophy includes all philosophical discussion about aims, methods, empirical findings, and consequences of neuroscience, as well as current attempts to clarify the relationship between brain states and mental states. According to Roth, major topics of neurophilosophy are: (i), the "mind-brain" -problem, including the nature of mental states and their relationship to brain states, particularly with respect to consciousness and mental causation; (ii), the relationship between the "outer" or "objective" and "the inner" or "phenomenal" world including the 335

336 Introductory remarks epistemological quest for certainty of perception and cognition; (iii), the problem of free will and culpability; (iv), the question of unique human as opposed to animal traits including the presence of mind and consciousness in animals; (v), the origin and function of the "self"; (vi), the origin of social and moral behaviour, and finally, (vii), ethical questions of neuroscience. In regard to the mind-brain problem, Roth pleads for the position of non-reductionist monism or physicalism. His examples for neurophilosophy present a current productive interaction between philosophy, psychology and neuroscience in the context of empirical mindbrain or consciousness research. However, further experiments need to be carried out to solve the mind-brain problem in a way acceptable for the representatives of all three disciplines. Roth leaves the question open, whether already existing physical concepts will be able to explain the "nature of mind" or whether new laws have to be discovered. 2. Buddha's conception that considered the kinds of cognition that can warrant valid knowledge. The relationship between mind or mental phenomena and the body was discussed with different proponents of Indian Materialism in order to prove the correctness of Buddha's analysis of the empirical person. Steinkellner surveys the concept of the senses, their nature and function according to a particular system of mainstream Buddhism, as well as of the ideas about the relationship between mental phenomena and the material body, as can be seen in the attempt of the influential Indian philosopher Dharmakirti to refute the reductionistic explanation of consciousness. Steinkellner leaves open the question of monism versus dualism. Instead he proposes to differentiate between the study of the physiological nature of the mind and the study of the social and epistemological nature of the mind and its functions useful to the species. Whereas the former study explains the mind's nature, the latter deals with the mind's function. Such a distinction, if considered as conventional practice, would neither devalue the progress of science in its efforts for a natural explanation of the mind, nor would it devalue ordinary human practice, which relies on the mind as one of the best tools in the strivings for survival. In "Sensory perception, body and mind in Indian Buddhist philosophy" Ernst STEIN KELLNER presents Buddha's conception of the nature of sentient beings. Some interpretations in subsequent Buddhist philosophical traditions appear astonishingly modern. Buddha's usage of defined abstract notions was limited to those necessary for presenting soteriological (related to salvation) and practical teachings and his approach proved to be philosophically useful. Basic concepts and theorems were soon developed into systems of ontology and psychology, which were followed by a normative epistemology 3. Eye of the mind, eye of the body In her chapter "The 'eye of the mind' and the 'eye of the body': Descartes and Leibniz on truth, mathematica, and visuality" Sybille KRAM ER discusses the conflict between rationalism and empiricism. Even though the rationalist is regarded as a philosopher whose source of knowledge is reason rather than sensory perception, the terminology of

Introductory remarks 337 "sight" plays a striking role in rationalist philosophy. This paradox of the simultaneous "devaluation" and "valuation" of seeing can be explained in terms of the difference between the "eye of the mind" and the "eye of the body". The rationalist transforms sight into the activity of reasoning, whereby the "intellectual eye" sees all the more clearly the more the body's eyes remain blind. Kramer's contribution corrects this understanding by looking at the epistemologies of Descartes and Leibniz. Her investigation into the epistemological meaning of the mathematical innovations of both philosophers helps rehabilitate the role of bodily sight in rationalist forms of knowing. Kramer suggests that the calculisation in mathematics, to which Descartes' analytical geometry and Leibniz's infinitesimal calculus contributed, promotes a specific type of visuality which she calls "tactile seeing" or "seeing with the hand." It is also shown, that traces of calculisation, in the form of the core rationalist move of reducing truth to correctness, can be found in epistemology. (i), according to Kramer, Hindu-Arabic arithmetic with its decimal positional notation is the prototype of the technique of calculisation. The basic idea behind the practice of calculation is the operative separation of construction and interpretation. Mathematics becomes a model for rationalist epistemology by virtue of its calculising problem-solving techniques ("more calculo") and not its axiomaticdeductive techniques of reasoning ("more geometrico"). (ii), Kramer shows the mathematical innovations: Cartesian analytical geometry translates geometric figures into algebraic formulas, so that only what can be rendered algebraically is considered part of scientific geometry. Descartes transforms mathematics into a kind of "language"; one, however, that "speaks" graphically to the eyes. With the help of a graphic signifying system, Leibniz's infinitesimal calculus introduces algorithmic arithmetic to higher analy- sis. Leibniz separates the operation with infinite values from their interpretation, so that the truth of a statement comes to rest solely on its internal correctness. (iii), the origins of Descartes' method are traced: it is no longer the object that determines the method, but the method that determines the object. This idea has its origins in algebraisation. Descartes' "Regulae ad directionem ingenii" demonstrates the exemplary role of algebra in two ways: Descartes appeals to the tradition of problem-solving analysis understood as liars inveniendi" and not to the Aristotelian proving analysis of liars iudicandi". Further, Descartes introduces an extensional, graphic symbolism meant to work like a calculus into his "mathesis universalis". Only that which can function as an object of reference of this symbolism can be admitted as an object of universal science. Visualization and methodology become enmeshed. (iv), Leibniz's reduction of truth to correctness is discussed. Leibniz articulates the concept of calculation as an interpretation-neutral operation with graphic signs and tries to apply calculisation as a universal process onto knowing itself. This shows that the objects of knowledge are constituted by the order of the process of knowing, according to Leibniz's "generative definition." Since the world is made up of unique things, but calculising knowledge only refers to abstract constructs of the mind, the epistemological consequences are that our formal knowledge can no longer refer to the real world, but only to our models of the world. (v), Kramer shows the process of visualising the invisible or "seeing with the hand": The heart of science is not simply "abstraction", but the sensualisation of abstractions and the visualisation of the invisible. Modern algebraisation stands for the formation of an "operative" or "tactile" kind of visuality. The rationalists devalue "ocular seeing," since it is closely tied with the illusionary, but they value "tactile seeing," which

338 Introductory remarks is not a "seeing with the mind," but a "seeing with the hand." 4. Free will In his contribution "Free will" Hans-Dieter KLEIN pleads for compatibilism. Free will can be defined at one extreme as libertarian free will, according to which free actions are unconstrained and uncaused by any physical process. It is therefore incompatible with the concept of the physical world as a closed causal system. However, due to the shortcomings of the common opinion that free will and physicalism are simply incompatible, the more sophisticated approach of the compatibilists rejects libertarian free will, because free will for compatibilists is not the absolute libertarian freedom. Rather, it is the unrestricted ability to act without external or internal (e. g. mental diseases) constraints. Moreover, compatibilists are aware that even in the determined world some processes are chaotic and their complex outcome cannot be predicted, although they are causally related to their starting conditions. This approach can be supported by a long philosophical tradition inaugurated by Aristotle. The conception that our free will is free in as much as the decision of the subject is not hindered by inner or outer compulsions goes back especially to Aristotle. Free of such compulsion, the freely deciding subject, in his opinion, determines himself, that is, through following the logical rules he relates the possible actions to self-produced norms, and makes his decision accordingly. Klein shows that free will so understood is not in opposition to a continuous physical causality. In fact, as the example of computers shows, thought processes can be physically realised. H-O K