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Nov 19 2010

On free will-9: Attempts to salvage free will

(For previous posts in this series, see here.)

People who are determined to keep the Ghost in the Machine alive still have a few options. Ironically, although it was Libet’s early experiments that cast doubt on the idea that we have free will, he himself was disturbed by that implication and has sought to find ways to salvage it. In his many publications, he repeats his belief that his experiments did not rule out free will and suggests ways in which it could still operate.

The source of his belief in free will is similar to the reasons that we all cling on to, that we strongly feel that we act freely and that it is not desirable to abandon belief in it. As he says, (Do we have free will?, Benjamin Libet, Journal of Consciousness Studies, vol. 6, No. 8–9, 1999, pp. 47–57):

However, we must recognize that the almost universal experience that we can act with a free, independent choice provides a kind of prima facie evidence that conscious mental processes can causatively control some brain processes (Libet, 1994). As an experimental scientist, this creates more difficulty for a determinist than for a non-determinist option. The phenomenal fact is that most of us feel that we do have free will, at least for some of our actions and within certain limits that may be imposed by our brain’s status and by our environment. The intuitive feelings about the phenomenon of free will form a fundamental basis for views of our human nature, and great care should be taken not to believe allegedly scientific conclusions about them which actually depend upon hidden ad hoc assumptions. A theory that simply interprets the phenomenon of free will as illusory and denies the validity of this phenomenal fact is less attractive than a theory that accepts or accommodates the phenomenal fact.

Of course, the idea that we should retain belief in free will simply because everyone believes in it and the alternative is unpalatable is hardly persuasive as a scientific argument. So in a later paper published in 2002 (Consciousness and Cognition, vol. 11, 291–299, 2002), Libet goes further and suggests that we are not entirely the slaves of our subconscious decisions to act because we retain the power to veto a decision at the last minute. He argues that veto decisions may not follow the same pattern of arising from prior unconscious neural activity because the decision to veto an act may arise from a different source than the decision to take a specific act and thus not follow the pattern of precursor behavior that he observed about the decision itself. It is thus possible that a veto decision could be freely made. He says (referring to himself in the third person):

However, Libet noted that the conscious function still had enough time to affect the outcome of the process; that is, it could allow the volitional initiative to go to completion, it could provide a necessary trigger for the completion, or it could block or veto the process and prevent the act’s appearance. There is no doubt that a veto function can occur. The argument has been made that the conscious veto process would itself require preceding developmental processes, just like a conscious sensory awareness. But Libet (1999) argued that the conscious veto in a control function, different from awareness per se, need not be a direct product of the preceding processes, as is the case for simple awareness.

Libet suggests that although our decisions to carry out an act may be involuntary, the veto is different, and thus provides a new understanding of the role of free will.

I propose, instead, that the conscious veto may not require or be the direct result of preceding unconscious processes. The conscious veto is a control function, different from simply becoming aware of the wish to act. There is no logical imperative in any mind–brain theory, even identity theory, that requires specific neural activity to precede and determine the nature of a conscious control function. And, there is no experimental evidence against the possibility that the control process may appear without development by prior unconscious processes.

The role of conscious free will would be, then, not to initiate a voluntary act, but rather to control whether the act takes place.

Free will that can only act to veto an involuntary decision seems a rather weak substitute for the real thing. Those who want a bigger role for free will can, if they wish, can go beyond Libet’s limited concept and postulate that a ghostly free will does decide and is the cause of the early unconscious neural activity but that for some reason it does not produce any brain activity and also hides its early decisions from us, perhaps by wiping out that initial memory and creating our conscious thoughts only much later. In other words, when we become consciously aware of making a decision, that awareness is merely an echo of the same decision that was made earlier prior to the unconscious neural activity, but of which we are not aware. Daniel Dennett’s theory of consciousness (Consciousness Explained, 1991) says the brain is constantly writing and rewriting our personal narratives of what we experience in order to create a coherent narrative so this kind of mental revisionism could explain why we are not conscious of our early conscious decisions.

But why would the brain bother to go to this level of subterfuge? It is hard to think of an evolutionary advantage that is conferred to the organism by the brain covering its tracks in this way. These kinds of explanations for free will soon start to look suspiciously like the pseudo-explanations religious believers give for why we cannot see any evidence for their peripatetic god even though he is supposedly always busy doing stuff.

But even allowing for the possibility that our brain somehow hides the existence of free will, this would not seem to offer much consolation. What would be the point of decisions that are made before we are conscious of making them? The idea of free will gets its power from the fact that we consciously make the decisions that trigger motor activity.

Next: Ethical and legal implications of free will as a veto power

1 comment

  1. 1
    Steve LaBonne

    I must confess that at the beginning of this series I had some doubts about your thesis that belief in “free will” is simply a covert form of substance dualism, since it has many defenders who appear not to be dualists. But reading this post has really nailed that thesis down for me. If people (even people as brilliant as Libet) can be so heavily invested in the mere question of whether or not a neural process leading to motor activity happens to be accessible to consciousness, I can’t make any sense of that degree of special pleading except on the supposition that at some level- more emotional than intellectual- they are still thinking of consciousness as involving something over and above brain activity.

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