NICK@AI.AI.MIT.EDU (Nick Papadakis) (06/02/88)
Date: Wed, 1 Jun 88 09:38 EDT From: "CUGINI, JOHN" <cugini@icst-ecf.arpa> Subject: Free will - the metaphysics continues... To: ailist <ailist@ai.ai.mit.edu> Reply-To: "CUGINI, JOHN" <cugini@icst-ecf.arpa> Drew McDermott writes: > I believe most of the confusion about this concept comes from there > not being any agreed-upon "common sense" of the term "free will." To > the extent that there is a common consensus, it is probably in favor > of dualism, the belief that the absolute sway of physical law stops at > the cranium. Unfortunately, ever since the seventeenth century, the > suspicion has been growing among the well informed that this kind of > dualism is impossible. ... > > If we want to debate about AI versus dualism, ...we can. [Let's] > propose technical definitions of free will, or propose dispensing with > the concept altogether. ... > > I count four proposals on the table so far: > > 1. (Propose by various people) Free will has something to do with randomness. > > 2. (McCarthy and Hayes) When one says "Agent X can do action A," or > "X could have done A," > > 3. (McDermott) To say a system has free will is to say that it is > "reflexively extracausal," > > 4. (Minsky et al.) There is no such thing as free will. I wish to respond somewhat indirectly by trying to describe the "classical" position - ie to present a paradigm case of free will. Thus, we will have an account of *sufficient* conditions for free will. Readers may then consider whether these conditions are necessary - whether we can back off to a less demanding case, and still have free will. I suspect the correct answer is "no", but I'll not argue that point too thoroughly. *** *** *** *** *** *** Brief version: Free will is the ability of a conscious entity to make free decisions. The decision is free, in that, although the entity causes the decision, nothing causes the entity to make the decision. *** *** *** *** *** *** (Rough analogy: an alpha particle is emitted (caused) by the decay of a nucleus, but nothing caused the nucleus to decay and emit the particle - the emitting [deciding] is uncaused). There's an unfortunate ambiguity in the word "decision" - it can mean the outcome (the decision was to keep on going), or the process (his decision was swift and sure). Keeping these straight, it is the decision-process, the making of the decision-outcome, that is uncaused. The decision-outcome is, of course, caused (only) by the decision-process. Discussion: I'm going to opt for breadth at the expense of depth - please read in non-nitpicking spirit. 1. Randomness - free will is related to randomness only in that both are examples of acausality. True, my uncaused decision is "random" wrt to the physical world, and/or the history of my consciousness - ie not absolutely predictable therefrom. That doesn't mean it's random, in the stronger sense of being a meaningless event that popped out of nowhere - see next item. 2. Conscious entity - free will is a feature which only a conscious entity (like you and me, and maybe your dog) can have - can anyone credit an unconscious entity with free will, even if it "makes a random decision" in some derivative sense (eg a chess-playing program which uses QM processes to vary its moves) ? "Consciousness is a problematic concept" you say? - well, yes, but not as much so as is free will - and I think it's only problematic to those who insist that it be reduced to more simple concepts. There ain't any. Free decisions "pop out" of conscious entities, not nuclei. If you don't know what a conscious entity is, you're not reading this. No getting around it, free will brings us smack up to the problem of the self - if there are no conscious selves, there is no free will. While it may be difficult to describe what it takes to be a conscious self, at least we don't doubt the existence of selves, as we may the existence of free will. So the strategy here is to take selves as a given (for now at least) and then to say under what conditions these selves have free will. 3. Dualism - I believe we can avoid this debate; I maintain that free will requires consciousness. Whether consciousness is physical, we can leave aside. I can't resist noting that Saul Kripke is probably as "well-informed" as anyone, and last I heard, he was a dualist. It's quite fashionable nowadays to take easy verbal swipes at dualism as an emblem of one's sophistication. I suspect that some swipers might be surprised at how difficult it is to concoct a good argument against dualism. 4. Physics - Does the requirement for acausality require the violation of known physical laws? Very unclear. First, note that all kinds of macro-events are ultimately uncaused in that they stem from ontologically random quantum events (eg radiation causing birth defects, cancer...). Whether brain events magnify QM uncertainty in this way no one really knows, but it's not to be ruled out. Further, very little is understood of the causal relations between brain and consciousness (hence the dualism debate). At any rate, the position is that, for the conscious decision-process to be free, it must be uncaused. If this turns out to violate physical laws as presently understood, and if the present understanding turns out to be correct, then this just shows that there is no free will. 5. No denial of statistical probabilitities or influence - None of the above denies that allegedly free deciders are, in fact, quite predictable (probabilistically). It is highly unlikely that I will decide to put up my house for sale tomorrow, but I could. My conscious reasons for not doing so do not absolutely determine that I won't. I could choose to in spite of these reasons. 6. Free will as "could have decided otherwise" - This formulation is OK as long as the strength of the "could" includes at least physical possibility, not just logical possibility. If one could show that my physical brain-state today physically determines that I will (consciously) decide to sell my house tomorrow, it's not a free decision. 7. A feature, not an event - I guess most will agree that free will is a capability (like strong arms) which is manifested in particular events - in the case of free will, the events are free decisions. An entity might make some caused decisions and some free - free will only says he/she can make free ones, not that all his/her decisions are free. 8. Rationality / Intelligence - It may well be true that rationality makes free will worth having but there's no reason not to consider the will free even in the absence of a whole lot of intelligence. Rationality makes strong arms more valuable as well, but one can still have strong arms without it. As long as one can acausally decide, one has free will. 9. Finding out the truth - Need I mention that the above is intended to define what free will is, not necessarily to tell one how to go about determining whether it exists or not. To construct a test reflecting the above considerations is no small task. Moreover, one must decide (!) where the burden of proof lies: a) I feel free, therefore it's up to you to prove my feelings are illusory and that all my decision-processes are caused, or b) the "normal" scientific assumption is that all macro-events have proximate macro-causes, and therefore it's up to me to show that my conscious processes are a "special case" of some kind. John Cugini <Cugini@icst-ecf.arpa> ------