Bruno Marchal's paper, Computation, Physis and Cognition English translation 1st draft
Introduction The computationalist hypothesis, or more simply, *mechanism*, which I consider here, is the hypothesis according to which *I* am a machine or *you* are a machine. The precise way in which I am interested in the hypothesis that we can survive, not just with an artificial heart or kidney, etc., but also with an artificial digital brain (finitely describable) assuming it is suitably configured at an adequate level. The aim is not to defend this hypothesis but to examine the consequences, notably concerning the mind-body problem. In particular I shall show, contrary to a very widespread belief, among philosophers and doctors as much as the layman, that mechanism is incompatible with materialism. I will demonstrate that mechanism is incompatible with materialist monism, which claims that is only one universe, which can in principle be described entirely in terms of physics. On the way I will demonstrate that mchanism is also incompatible with dualism, which holds that there is simultaneously a tangible world (described by physics) and a mental world. Hence I will show that mechanism necessitates a monist idealism incompatible with any form of materialism. This proof will not resolve the mind- body problem, but will lead towards a new formulation of the question. Essentially, with the computationalist hypothesis, the mind-body problem is transformed in the research deriving: 1. a phenomenology of mind - capable of explaining the origin and nature of knowledge and belief; and 2. a phenomenology of matter, capable of explaining the origin and nature of our observations and our theories of physics. The first point can hardly be considered original. With computationalism, psychology is, *in principle*, trivially reduced to information theory. The originality is in the demonstration that to resolve the body-mind problem, one is obliged to derive the phenomenology of matter from the phenomenology of mind. That is, physics is *in principle* a branch of psychology. This is precisely the reverse of our usual attempts to reduce or try to understand psychological phenomena from the substrate of the brain - physical, or even cosmic or universal. On the contrary, mechanism demands a psychology which eliminates all materialist ontology rather than a materialism which eliminates mental ontology. Mechanism therefore requires us to consider physics as a branch of psychology, itself a branch of information theory, which is in turn a branch of number theory. The word, "branch" is used here in a slightly more general sense than normal; this will be clarified during the course of the proof. An attentive logician will note that matter is not *logically* eliminated. But he would fail at any attempt to explain physical sensations through physical science alone. There is a certain irony in this situation. Mechanism is generally invoked by reductionist materialists to debunk the spirit and to counter dualism and other spiritualism. And it works in practice, but on closer examination (as proposed here), the dematerialisation does not stop with the spirit but extends to the body, matter and the universe. This work is not speculative. It stands up well to demonstration or hypothetico-deductive argument: IF mechanism is true THEN physics *must* be derived from psychology. I clarify this point in Chapter 2. Note on methodology To help the reader keep track of the proof, I decided to be as brief as possible. The poof, which starts in Chapter 3, finishes by the end of Chapter 4. It does not assume any specific knowledge, except a familiarity with Church's Thesis and, of course, a smattering of high-school classical philosopy (good treatments are given in Huisman and Vergez, 1996 or Nagel, 1987). Appendix D provides an introduction to the mind-body problem as well as some supplementry definitions on the concept of sufficient conditions for mechanism. Chapter 1, which defines the hypotheses of the *entire* work, raises some technical points which are not ued in the proof. This additional material will be used before Chapter 5. Chapter 5 examines the search for a solution to the mind-body problem in the light of the proof given here. Unlike the proof, this research has a few prerequisite techniques. You may consult the technical report (Marchal, 1995) or the appendices of this paper, or certain works such as Boolos, 1995, Webb, 1980, as well as Albert, 1992 and Maudlin, 1994 on physics.