Robert Kane is the acknowledged dean of the libertarian philosophers writing actively on the free will problem. Before Kane, in the late twentieth century, Anglo-American philosophers had largely dismissed free will as a "pseudo-problem." Although like the others, Kane does not find any libertarian position "intelligible," he developed the view that even if most of our actions are determined entirely by our character, these "self-formed actions" can be free if we at times in the past freely created our own character (and if we remain free to change it). This was Aristotle's view and agrees with Buddhist ideas of Karma.

In addition to his work to find some pathway through the "free will labyrinth" to an intelligible account of freedom, Kane has assembled in his massive 2002 sourcebook The Oxford Handbook of Free Will perhaps the best survey of modern positions on free will, from theology and fatalism to metaphysical libertarian perspectives.

The Handbook has contributions from over two dozen contemporary philosophers with strong ideas about free will. Sadly most continue to be wordy jargon-laden debates and attempts to logically refute one position or another. They reflect the fact that Peter Strawson changed the subject of the discussions from free will to moral responsibility and Harry Frankfurt changed the debate from free will to the existence of alternative possibilities.

That there is little new and that it is dismissive of freedom as unintelligible, makes the Oxford Handbook an accurate reflection of the current state of the free will problem. Kane insightfully remarks "One may legitimately wonder why worries about determinism persist at all in the twenty-first century, when the physical sciences - once the stronghold of determinist thinking - seem to have turned away from determinism."

In his 1985 book Free Will and Values, aware of earlier proposals by Eccles, Popper, and Dennett, but working independently, Kane proposed an ambitious amplifier model for a quantum randomizer in the brain - a spinning wheel of fortune with probability bubbles corresponding to alternative possibilities, in the massive switch amplifier tradition of Compton and Gomes.

Kane's work is squarely in the tradition of several other brain mechanisms proposed to underlie the free will.

• James Clerk Maxwell's "Singularities" (1856)
• Arthur Stanley Eddington's "Free Electrons" (1928)
• Arthur Holly Compton's Photocell Amplifier (1931)
• John Eccles' "Critically Poised Neurons" (1953)
• A. O. Gomes' Quantum Composer (1964)

Kane's work is squarely in the massive switch amplifier (MSA) tradition of Compton and Gomes.

Kane says (p.169):

What I would like to do then, is to show how an MSA model, using Eccles' notion of critically poised neurons as a working hypothesis, might be adapted to the theory of practical, moral and prudential decision making.

Keeping these points in mind, let us now suppose that there are neurons in the brain "critically poised" in Eccles' sense, whose probability of firing within a small interval of time is .5. (We shall tamper with this simplifying assumption in a moment.) For every n such neurons, there are 2ⁿ possible ordered combinations of firings and non-firings, which may be represented by sequences, such as (101... ), (01101... ), where the "1" 's indicate firings, the "0" 's non-firings, and the dots indicate that the sequences are continued with "0" 's up to n figures. A reasonably small number of such neurons, say a dozen, would yield ordered combinations, in the thousands, enough for the purposes of the theory. As indicated in 8.4, the exact number of possible alternatives or partitionings does not matter so long as it is large; it would likely depend on the exigencies of neurological programming rather than the demands of the theory.

For practical choice, these ordered combinations of firings and non-firings of critically poised neurons would correspond to places on a spinning wheel, most of which would give rise to chance selected considerations, opening doors to consciousness of possibly relevant memories, triggering associations of ideas and/or images, focussing attention in various ways, etc. Some combinations of firings and non-firings might draw a blank. But the wheel would keep spinning until it hit something worth considering, so long as the practical reasoner or creative thinker were in a receptive, yet reflective, state of mind. Then the relevance of the consideration to deliberation would have to be assessed and the consideration either accepted or rejected.

Kane introduces a probability bubble.

One might think of this as a picture of an air bubble in a glass tube filled with a liquid, with the lines A and B marked on the outside of the glass as on an ordinary carpenter's level. But this description is merely an aid to the imagination. We are going to give the bubble some extraordinary properties. The bubble may represent either the desire to choose to act from duty (out of equal respect) or the effort made to realize this desire in choice. The respective desire and effort are conceptually related because the desire is defined as the disposition to make the effort; and the intensity of the desire is measured by the intensity of the effort. The lines A and B in the figure represent choice thresholds. If the bubble passes above the line A, the choice is made to act from duty; if it passes below B, the choice is made to act on self interested motives. When the bubble is between the lines, as in the figure, no choice has yet been made. A downward pull of gravity in the figure may be thought to represent the natural pull of one's self interested motives, which must be counteracted by an effort to resist temptation.

There is an ambiguity, essential to our problem, about what it means to say that the bubble "passes above" the line A, or "below" the line B. If the bubble passes above A, or below B, then the choice is made to act from duty, or from self interest, respectively. But does this mean that the bubble must be wholly, or only partly, above A, or below B? It is here that we give the bubble some extraordinary properties. We imagine that the bubble represents a probability space, so that, when it is partly above A, there is a corresponding probability, but not certain that the choice is mate to act from duty, and when it is partly below B there is a corresponding probability, but not certainty, that the choice is made to act from self interest. When the bubble is wholly above A (or below B), it is certain that the choice is made to act from duty (or self interest). We then imagine a point particle in the probability space (the bubble) that moves around randomly, while always remaining within the space. That is, it has an equal probability of appearing in any one of a number of equal sized regions in the space. (There will be further comment on this partitioning and its significance in a moment.) If part of the bubble is above the line A for a certain time and the point particle is in regions all of which are wholly above the line for the same length of time, then the choice is made to act from duty (and similarly for line B).

To complicate matters further, we want to assume that the bubble or probability space does not have an exact position vis a vis the thresholds at any given time and that this inexactness of position is also due to the undetermined movement of the point particle in the regions. There are a number of ways to represent this in the diagram, but the simplest way is the following. Imagine, as in the following figure, that the choice thresholds A and B have indeterminate position so that they can be anywhere between (or on) the extremes A'-A" and B'-B" respectively:

The distances between any two possible threshold positions for A (or any two for B) are equal and each possible threshold position corresponds to a region in the bubble such that, if the point particle is in that region, the threshold is at the corresponding position. But adjacent regions in the bubble need not correspond to adjacent positions of the thresholds and higher or lower regions of the bubble need not correspond to higher and lower threshold positions respectively.

What all this means is that the intensity of the effort to overcome temptation at any given time, which is measure of the intensity of the desire to act from duty (represented by the position of the bubble vis a vis the thresholds and the position of the point particle within the bubble) is indeterminate. And, as a consequence, the outcome of the choice situation at a given time is undetermined and unpredictable as long as the bubble is not wholly above A' or wholly below B".
(Free Will and Values, p.144-6)

Kane's model combines free will and values. Kane claimed his free choice is moral and made in accord with Kant's concept of duty versus one's self-interst or desires. This is the ethical fallacy. Freedom is merely a prerequisite for responsibility.

"the succession of random selections among equiprobable alternatives is meant to be a continuing reminder (a mental or neurological representation) of the fact that the reason sets of other persons are to be treated equally."

Kane's model is also "restrictive," a term coined by John Martin Fischer to describe Peter van Inwagen's claim that only a tiny fraction of our decisions and actions could be free actions. For van Inwagen, it is those which have closely balanced alternatives (the ancient problem of the liberty of indifference. For Kane, it is those rare and difficult decisions that are deeply moral. They are those moments in which are character is formed. Later decisions made consistent with our character and values can then be traced back to these "self-forming actions." This provides us with what Kane calls ultimate responsibility or UR.

The first step in this rethinking is to note that indeterminism does not have to be involved in all acts done "of our own free wills" for which we are ultimately responsible. Not all acts done of our own free wills have to be undetermined, only those acts by which we made ourselves into the kinds of persons we are—namely, the "will-setting" or "self-forming actions" (SFAs) that are required for ultimate responsibility.

Now I believe that these undetermined self-forming actions, or SFAs, occur at those difficult times of life when we are torn between competing visions of what we should do or become. Perhaps we are torn between doing the moral thing or acting from ambition, or between powerful present desires and long-term goals; or we may be faced with difficult tasks for which we have aversions. In all such cases of difficult self-forming choices in our lives, we are faced with competing motivations and have to make an effort to overcome the temptation to do something else we also strongly want. There is tension and uncertainty in our minds about what to do at such times, let us suppose, that is reflected in appropriate regions of our brains by movement away from thermodynamic equilibrium—in short, a kind of "stirring up of chaos" in the brain that makes it sensitive to micro-indeterminacies at the neuronal level. The uncertainty and inner tension we feel at such soul-searching moments of self-formation would thus be reflected in the indeterminacy of our neural processes themselves. What we experience internally as uncertainty about what to do on such occasions would correspond physically to the opening of a window of opportunity that temporarily screens off complete determination by influences of the past.

Kane is not satisfied with his solution. He explains that the main reason for failure is

"locating the master switch and the mechanism of amplification...We do not know if something similar goes on in the brains of cortically developed creatures like ourselves, but I suspect it must if libertarian theories are to succeed." (p.168)

Kane admits his basic failure is his location of indeterminism in the decision process itself. This makes chance the direct cause of action.

But Kane claims that the major criticism of all indeterminist libertarian models is explaining the power to choose or do otherwise in "exactly the same conditions," something he calls "dual rational self-control." Given that A was the rational choice, how can one defend doing B under exactly the same circumstances?" (p.59) Kane is concerned that such a "dual power" is arbitrary, capricious, and irrational.

Apart from the fact that information-rich systems with a history are never in the exact same conditions, and ignoring the fact that random alternative possibilities are unlikely to repeat, an adequately determined will would very likely make the same choice, for the same reasons, from the same set of alternative possibilities. But it might on the other hand exercise its irrational prerogative! We humans are unpredictable, which makes us occasionally capricious and arbitrary. So why the problem?

Writing about his probabilistic solution thirty years later, Kane insightfully suggested that information theory may help understanding the problem of will. He proposes that the role of indeterminism is as an ingredient in the teleological process of will. But rather than making it the generator of possibilities and a creative force, Kane considers it a hindrance or obstacle to the attainment of the goal.

For Kane, this is actually beneficial because "noise or static" in information transmission might garble messages and thus raise the level of effort needed for a moral decision. It is odd that he does not consider the random noise as a generator of alternative possibilities.

In 2005, Kane wrote perhaps the most significant analysis of a two-stage solution like our Cogito mind model and the suggestions of William James, Henri Poincaré, Arthur Holly Compton, A.O. Gomes, Karl Popper, Henry Margenau, Daniel Dennett, and Alfred Mele.

The final libertarian theory I want to consider in this chapter takes a very different approach to explaining libertarian free choices. This view rejects both simple indeterminism and agent-causation. Instead it focuses on the process of deliberation. When we deliberate, for example, about where to vacation or which law firm to join, many different thoughts, images, feelings, memories, imagined scenarios, and other considerations pass through our minds. Deliberation can be quite a complex process. When Mike thinks about Hawaii, he pictures himself surfing, walking on sunny beaches, eating in his favorite Hawaiian restaurants; and these various thoughts incline him to choose Hawaii. But he also thinks about skiing, sitting by a fireplace after a long day on the slopes, and visiting with friends he knows in Colorado; and he leans toward Colorado. Back and forth he goes, until after a period of time considerations on one side outweigh the others and he finally chooses one option. (Unless, of course he is one of those indecisive types who finds it hard to make up his mind.)

Note that our free thoughts appear to "come to mind"

In the course of such deliberations — which may sometimes take hours or days and may be interrupted by daily activities — new thoughts, memories or images can often come to mind that influence our deliberations. Mike may suddenly remember a lively nightclub he visited in Honolulu when he was last there — great music, great girls — and the idea of going back to this place gives him an added reason to favor Hawaii, a reason that hadn't previously entered his deliberation. Other images that flit through his mind may turn him against Hawaii. Imagining himself out on the beach all day, suddenly he remembers his doctor's warning about not getting too much sun if he wants to avoid skin cancer.

Now one could imagine that some of these various thoughts, memories, and imagined scenarios that come to mind during our deliberations are undetermined and arise by chance and that some of these "chance selected considerations" might make a difference in how we decide. If this were to happen in Mike's case, the course of his deliberation, hence his choice, would be undetermined and unpredictable. A Laplacian demon could not know in advance which way Mike would go, even if the demon knew all the facts about the universe prior to Mike's deliberation, for these facts would not determine the outcome. Yet Mike would still have control over his choice in a certain sense. He could not control all the thoughts and imagined scenarios that come to mind by chance. But he would be in control of how he reacted to those thoughts and imaginings once they did occur. And his choice of Hawaii in the end would be perfectly rational, not arbitrary, if the weight of all the considerations that did come to mind (some of them by chance) weighed in favor of Hawaii. In this way, choices could thus be controlled and rational even though indeterminism was involved in the deliberations leading up to them.

A view of this kind is called causal indeterminism or event–causal libertarianism, for it allows that our thoughts, images, memories, beliefs, desires, and other reasons may be causes of our choices or actions without necessarily determining choices and actions; and yet this view does not postulate any extra kind of agent-causation either. Two philosophers who have suggested causal indeterminist views of this kind (without endorsing them), Daniel Dennett and Alfred Mele, argue that a view of this kind would give libertarians at least some of the important things they demand about free will. Such a view, for example, provides for an "open future," such as we think we have when we exercise free will. We would not have to think that our choices and the future direction of our lives had somehow been decided long before we were born. Nor would it be possible for behavioral engineers to completely control our behavior as in Walden Two or for Laplacian demons to know what we were going to do, if chance considerations might enter our deliberations.

Yet, as Dennett and Mele also admit, a causal indeterminist view of this deliberative kind does not give us everything libertarians have wanted from free will. For Mike does not have complete control over what chance images and other thoughts enter his mind or influence his deliberation. They simply come as they please. Mike does have some control after the chance considerations have occurred.

The evaluation of alternative possibilities is of course only adequately determined

But then there is no more chance involved. What happens from then on, how he reacts, is determined by desires and beliefs he already has. So it appears that he does not have control in the libertarian sense of what happens after the chance considerations occur as well. Libertarians require more than this for full responsibility and free will. What they would need for free will is for the agent to be able to control which of the chance events occur rather than merely reacting to them in a determined way once they have occurred.

Yet, as Mele points out, while this causal indeterminist view does not give us all the control and responsibility that libertarians have wanted, it does give us many of the things they crave about free will (an open future, a break in the causal order, etc.). And it is clearly a possible view. Perhaps it could be further developed to give us more; or perhaps this is as much as libertarians can hope for.
(A Contemporary Introduction to Free Will, p.64-5)

Kane seems to want his freedom both ways. He wants the agent to "control which of the chance events occur" and he also wants chance to be involved at the decision stage to prevent its being "determined."

He leaves himself vulnerable to the standard argument against free will. He does not see that we must unpack "free will" into "free" and "will."

Kane does notice that our thoughts "come to us" and that control, if we have it, insures that our actions "come from us." Our willed actions "depend on us," as Aristotle required.