Uwe Meixner is a philosopher of logic with theological interests who makes the case for a dualistic conception of mental causation. He interprets indeterministic events as opening a door to nonphysical causation by denying causal closure, the idea that everything in the world is determined by physical causes:Meixner's thinking seems consistent with two-stage models of free will, which generate alternative possibilities for action, which are then left to the agent (the self) to deliberate, evaluate, and select from. Meixner sees a connection with the indeterministic element that must be a part of biological evolution.
what about the nonphysical causation of physical events without equivalent physical causation, say, without any accompanying physical causation at all? Would not the occurrence of nonphysical causation of physical events without accompanying physical causation get into conflict with physics? It would not, not even under the metaphysical supposition that the physical world is a closed system: because an instance of nonphysical causation of a physical event without accompanying physical causation would leave the sum total of energy and momentum unchanged. It would merely involve a redistribution of energy and momentum. Redistributions of energy and momentum are, of course, happening constantly, and normally, it seems, one need not invoke nonphysical causation for having them come about. But, as most modern physicists hold, at least some of these redistributions are not determined by the energy/momentum distributions of the past.3 If this is true, then the physical past leaves a lacuna of determination that need not be left entirely to chance, but that can be, at least partly, filled by additional determination coming purely from a nonphysical source. In an indeterministic physical world, there is room for the nonphysical — specifically, the nonphysical mental — causation of physical events without accompanying physical causation.Meixner's arguments are consistent with an immaterial source of downward causal control by the mental, such as that proposed in our model of information as an emergent dualistic substance. Meixner says that what he calls "Purely nonphysical"
mental causation of the physical would originate in the mental subject, in the nonphysical individual, wholly present at each moment of its existence, which is the centre of consciousness: in the nonphysical substantial self. Since purely nonphysical mental causation of the physical presupposes physical indeterminism and originates in a substantial nonphysical mental agent, I will also call this kind of causation free nonphysical agency.Meixner sees the external physical world as a source of macroscopic indetermination:
The difficult question is how the nonphysical mental subject manages to do all this. If there is an answer, it must be provided by the brain.Meixner argues that not only microscopic (subatomic) indetermination is present in the body (brain), but also macroscopic indetermination. This is the idea of amplification of uncertainty. I maintain that the brain is, among other things, (1) an instrument for the detection of macroscopic indetermination in the environment of the organism (which environment includes, as its limit, the organism itself) and (2) an instrument for restricting the detected macroscopic indetermination to the advantage of the organism. In short, I maintain that the brain is a DOMINDAR:Detector Of Macroscopic INDetermination, And Restrictor.This is a bold assertion because it has not seemed to most philosophically tuned people that there is enough macroscopic indetermination in the physical world to be detected or restricted by anything. This, I believe, is a false impression.
From the indetermination the brain notices, it selects the indetermination worth reporting according to relevancy (for the survival, or at least the wellbeing, of the organism) and restrictability (since the biological point of detecting and reporting indetermination is to subsequently restrict that indetermination advantageously)... Finally, the indetermination selected by the brain as worth reporting is classified according to relative importance, so that the self, in consciousness, is ultimately presented with a relatively clear spectrum of weighted alternatives open to it. Then the decision what to do is up to the self.
If determinism ruled in the physical macro-world, then there would be nothing in that world that needed controlling, and hence nothing would need to be monitored or governed by any organ. For under determinism, everything happens automatically, with absolute precision and with inexorable necessity. Thus, unless there is indetermination of considerable extent in the physical macro-world, the emergence of brains is absolutely pointless from the evolutionary point of view. blockquote>
Under macroscopic physical determinism, the structural complexity of every apparatus, natural or artificial, is pointless that makes in advance provision for realizing at a time t one or another of several incompatible alternatives regarding the physical macro-world. where each of these alternatives is possible at time t. Why provide for the realization of one or another among several such alternatives — even if only in such a manner that the realization merely amounts to a law-determined reaction to a given physical condition, as in a multi-possibility reactor — if, under macroscopic physical determinism, it is true of only one thing at any moment in time that it can happen in the physical macro-world (namely, the one that does in fact happen)? When evolution ran a course that led, let’s suppose, merely by (microscopic) accidental mutation and subsequent natural selection to the development of macroscopic devices that are geared for implementing choices (made — by the devices themselves or by something else — between at least two incompatible alternatives that are each possible at the time in question), had evolution then forgotten that macroscopic physical determinism is true? Was it ignoring it?
I am of course not saying that the development of the above mentioned devices for implementing choices is logically incompatible with macroscopic physical determinism; for this determinism could, in principle, be of such a kind that the emergence of, say, multi-possibility reactors was itself determined. This would be an absurd — that is, an unnecessarily expensive — course for nature to take, and therefore a rather unlikely course (even for a complete mechanist regarding nature it remains true that nature normally follows the course which is themost economical), but it is not a logically impossible one. Therefore, in asserting that if determinism ruled in the physical macro-world brains would never have developed, I am relying on an implicit inference to the best explanation... I prefer to regard the impressive emergence of brains in the course of evolution as an indication of the great extent to which the terrestrial physical macro-world is undetermined (prior to additional determination). Given this massive macro-indetermination, the unpredictability with which brains are confronted in their monitoring and governing activity must indeed more often than not betoken indetermination.
Two Models of Action-Determination: Chance-Generator and Decision-Maker [perhaps Two-stage Models?] Once it is accepted that the brain is often right in translating unpredictability as indetermination, and as indetermination about which something can be done (via the brain), the question arises in what manner it is determined what will be done; that is, the question arises in what manner it is determined how the detected indetermination will be restricted. There are two salient models for this. The first model — where the brain is a DOMINDAR in its own right — can do without consciousness; it simply consists in this: the brain contains a physical chance generator (that is, a generator of genuine physical chance events: physical events without sufficient cause), and determining which alternative to realize fromthe several realizable alternatives the brain has detected is left to cerebral gambling (and subsequent mechanical cerebral processes), for which procedure consciousness is not essential. The second model — where the brain is a DOMINDAR instrumentally for something else — cannot do without consciousness; for, according to it, consciousness is precisely the nonphysical medium in which the several realizable alternatives the brain has detected are presented by the brain to the nonphysical self (under normal conditions, quite faithfully), who then, in the light of consciousness, makes an at least rudimentarily rational decision regarding which alternative to realize. This decision may, but need not necessarily, be preceded by deliberation, and under normal conditions it is quite faithfully put into effect by the brain. It far too often turns out to be the correct decision for it to be with any likelihood the result of a mere chance process. The instigation by the self of the brain to go into action in a certain manner is indeed an occurrence of nonphysical causation of the physical without accompanying physical causation. But this occurrence of nonphysical causation of the physical cannot interfere with physical causation and the laws of physics, because it is purely and simply the beginning of the realization of one among several physical possibilities — involving brain, rest of the body, and outer environment—that the laws of physics, the entire physical past and therefore the sum total of physical causation could not by themselves exclude from happening.
The Two Sides of BeingDuring his 2001/2002 academic year spent at Notre Dame (where one "can use the word 'soul' ... and they don't snicker"), Meixner began work on his monumental defense of dualism The Two Sides of Being: A Reassessment of Psycho-Physical Dualism. Physicalism is the modern term for materialism, he says, and he surveys the materialist philosophers who attack "dualist" concepts like mind, self, soul, spirit, consciousness, experience, as so many "illusions." His chief targets are Daniel Dennett, John Searle, David Chalmers (though Searle and Chalmers oppose Dennett), the Churchlands, Colin McGinn, Richard Swinburne, and Derek Parfit.