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ピンカーも避けて通った自由意思と責任について脳についての自然科学的知見といかに両立するかを意識についての整理と進化についての理解を踏まえて真正面から哲学として論じています.
前半の因果関係の部分とか結構興味深い議論(刑法の議論を復習してしまいました.日本刑法の解釈では相当因果関係とかいってお茶を濁しているが考え込むと結構深い問題に行き着くのをはじめて認識)もあったりもするのだが,後半は私の方が息切れ,これだけ進化生物学を踏まえていてもやっぱり哲学書を原書で読むのは疲れます.しかし本書の端々から西洋知識人としてはニューラルネットワークとしての脳を認めると自由意志がないことになり責任を巡る非常に深刻な問!題について避けて通れないのが逆に良くわかります.
決定論を避けるために量子論を持ち出すことはまったくのナンセンスである,そして進化的な選択肢の増大(そして避けることができるかどうか)を考えれば十分自由意思と責任を認めることができるというのが本旨.途中コミットメントにも触れて選択肢を狭めることが問題解決に役に立つあたりについての議論もちょっと面白い.
哲学者の議論については「バカの壁」(関係ないけどこの養老先生の造語はいいね)を崩すのにこんなにも苦労するものなのかというのがふと感じた感想です.
His basic effort is to reconcile the determinism of Darwinism with the humanist's concern with human freedom. To do so he jettisons the notion that free will is a metaphysical concept. Rather, he explains it in terms of contemporary objective science, specifically via the same sort of evolution that led to the development of the eye or of language. He relies heavily on Richard Dawkin's concept of the evolution of memes: ideas that compete with each other just as other characteristics do via natural selection. In other words he argues that freedom of will grows and evolves. To achieve this conclusion he makes the point that determinism (a cause mechanistically producing an effect) is not the same as inevitability. He uses an example from baseball (shades of the late Stephen Jay Gould!) to make his point. He says that a batter has a choice of turning away from a pitch that is going to hit him or allowing it to hit him, depending on which action will help his team. His action is not determined by the prior history of the universe, but by his own analysis in the moment. In a different game, he might make a different choice. This, and other similar arguments, lead Dennett to the conclusion that the more we know, the more varieties and degrees of freedom we can have. Thus, modern man has more freedom than did, say, the Neanderthal.
Essentially then, Dennett, whose earlier work in the areas of consciousness (another concept that gives determinists fits) are seminal, asserts that natural science is the ally of freedom, not an argument against it. The audacious arguments he posits to support this position are breathtaking in their scope and are, for this reader, convincing.
The problem with this book, as far as I am concerned, is that it feels rushed and disjointed. I was more than happy to read all 500+ pages of DDI because the topic deserved that much space and, honestly, that book is a pleasure to read. The topic of free will, if anything, requires even more space to develop, and I would have gladly sat through six or seven hundred pages if necessary. As it is, my understanding of Dennett's arguments is sketchy - even after letting them sink in a few days and re-reading a few sections - so sketchy, in fact, that I won't attempt anything like a synopsis here, for fear of bungling the job. Beyond that, I was a little annoyed with the amount of recycled material from CE and DDI.
So why is Daniel Dennett's task a thankless one? Because he insists that free will is not an "illusion" as some hardcore materialists claim - nor is it some "extra something" in the sense implied by traditional dualist philosophers. There are a lot of feathers to ruffle in this area. Affirming free will on a strict materialist basis would be quite a feat, if done clearly and convincingly. I believe that case can be made, and that it should be made, and that Dennett is qualified to make it. Unfortunately, in Freedom Evolves he didn't do so as clearly and convincingly as I wish he had. Until Dennett or somebody else does so, the task will remain long overdue.
For those who wonder about the conditions that foster human freedom and those that suppress it, this book doesn't quite delve into political or social philosophy per se, but it is at least a start at a real answer by providing clear thoughts and useful science and meta-science.
One very good reason for this book is that while Dan Dennett is a clear and vivid writer, particularly for a philosopher, he is also frequently rather badly misunderstood for some reason.
He has been described by reviewers as denying that human beings have free will or conscious awareness, and he has been accused of being an "ultraDarwinist," although he himself disputes these claims. In Freedom Evolves, he ties his previous ideas together and presents them in a way that will resist these misinterpretations of his ideas.
First, Dennett defends the compatibilist tradition (where free will and determinism are considered compatible in principle). He believes that the universe is probably deterministic in its physical nature, but that this doesn't mean our lives are pre-determined, nor does it prevent us from having forms of freedom worth working and fighting for.
This is done by distinguishing determinism clearly from inevitability with the help of his perspective tool of
different 'stances.' The 'stances' help see causation in different terms: mechanical causes from a physical stance vs.
functional causes from a design stance vs. the action of intentional agents from an intentional stance. We perceive inevitability in causal models from the design stance. Then we get confused between free will and determinism because we apply inevitability back to the physical, where it simply doesn't happen.
Then he builds a non-Cartesian account of choice and agency. Rather than distinguishing mind from mechanicals,
he describes different kinds of agency arising as the result of different raw materials available at different times and places. He uses the "toy model" of Conrad's Game of Life as an intuition pump to show how the appearance of agency arises from Darwinian algorithms through patterns like anticipating and avoiding harm.
The fact that the game is implemented on a device that follows instructions to the letter makes it a tough sell I think, and not entirely convincing (something he is acutely aware of, but can't seem to do anything about).
The human kind of agency is introduced by a much clearer discussion of Libet's "half second delay" experiments than he provided in "Consciousness Explained." He makes the point much more directly here how the half second delay can reflect a distributed decision making process rather than demonstrating that "we" are not in charge of our own actions, as the interpretation sometimes goes.
He still follows the basic interpretation used by Tor Norretranders in "User Illusion" and Dan Wegner in
"Illusion of Free Will," (which he has a lot to say about, mostly very good). The fact that there is a reliable
readiness potential prior to reporting our decision to act does mean that in some sense "I" don't directly initiate my actions. But Dennett further shows how we are shrinking this "I" too far when we use this argument to claim that "we" aren't in control or that a mysterious unconscious mind is in control.
"We" are able to disavow responsibility for our own actions under these contrived conditions because we break in
to the middle of the distributed process of decision making. Libet's results demonstrate the separate operation of the parts comprising the whole process, and the flexibility of our sense of self, not the ultimate powerlessness of the "I". This discussion is a high point of the book.
In building a case for the power of the "I" to take responsibility and form committments, Dennett does a brief
review of the literature on evolutionary game theory and the role of committment problems in human social life. He then makes his most important and final argument, that the capacities evolved to solve these problems have become the basis, through cultural evolution, of a fragile and socially and culturally nurtured and exercised ability to internallize reasons for behavior through reflecting on them and communicating them.
The idea that freedom, in the sense used in Dennett's final argument, is so real and yet so fragile is seen in the
way it can be heavily influenced simply by what we believe about it. The metaphor of "bootstrapping" runs throughout
the book, having been introduced in terms of the children's story of Dumbo the elephant. In some sense, we actually rely on useful illusions, such as the 'magic feather' that boosts Dumbo's confidence enough for him to try to fly. A crow flies up to shatter the useful illusion by grabbing the feather away. Dennett refers back to our frequent attempts to "stop that crow !" at various points in the book, pointing out where we may possibly be building real qbilities on the scaffolding of useful illusions, and trying to determine where the scaffolding can potentially be taken down once the real ability is in place.
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