So far this is the standard argument against free will.

Kosslyn then considers Daniel Wegner's analysis of Benjamin Libet's research, which implies that, "Even if one has time to override one's unconscious urges, there's no free will at work if one's conscious decisions are themselves determined."

But then Kosslyn notes that the opposite of being "determined" is not necessarily being "random," - a distinct departure from the standard logical argument. He then considers a way in which the brain may keep the door open for Libet's idea of free will.

1. Libet is right to focus on consciousness when theorizing about free will: In order to employ free will, one must evaluate information in working memory. Such information includes the alternative choices, the rationales for each, and the anticipated consequences of making each choice (although not all this information must be in working memory at the same time). If an external force coerces us, or we are operating on "automatic pilot," we are not exercising free will.

2. The rationales and anticipated consequences — and even, depending on the situation, the alternative courses of action — are not simply "looked up" in memory, having been stashed away like notes in a file after previous encounters.

Here Kosslyn considers a first stage of free creation of alternative courses of action

Rather, one constructs rationales and anticipated consequences, as appropriate for the specific situation at hand. This construction process may rely in part on chaotic processes. Such processes are not entirely determined by one's learning history (even as filtered by one's genes). By analogy, consider the path of a raindrop dribbling down a pane of glass. It zigs, it zags, tracing a path best explained with the aid of chaotic principles. The same raindrop, striking precisely the same place on that pane on a warmer day (which would cause the glass to be in a slightly different state) would take a different path. In chaotic systems, very small differences in start state can produce large differences downstream. The pane of glass is like the state of the brain at any instant. Depending on what one was just thinking about, the brain is in a different "start state" (i.e., different information is partially activated, different associations are primed) when one constructs rationales and anticipated consequences — which will affect how one decides. (Note that this idea does not simply move the problem back a step: What one was just thinking itself was in part a result of nondeterministic processes.) Our thoughts, feelings and behavior are not determined; we can have novel insights as well as "second thoughts."

3. Given the choices, rationales, and anticipated consequences, one decides what do on the basis of "what one is" (mentally speaking, to use Strawson's term, which includes one's knowledge, goals, values, and beliefs).

Here Kosslyn considers a second stage of willed decisions that are determined by our goals, values, and beliefs - "what one is"

"What one is" consists in part of information in memory, which plays a key role in the processes that construct the alternatives, rationales, and anticipated consequences. In addition, "what one is" governs how one actually makes the decisions. And making that decision and experiencing the actual consequences in turn modifies "what one is," which then affects both how one constructs alternatives, rationales and anticipated consequences and how one makes decisions in the future. Thus, with time one's decisions construct what one is.

We are not simply accumulators of environmental events, filtered by our genetic make-ups. We bring something novel and unique to each situation — ourselves. Nietzsche (1886, as quoted in Strawson, 1994, p. 15) commented, "The causa sui is the best self-contradiction that has been conceived so far." Maybe not.

4. This brings us back to the implications of Libet's discovery, and suggests a way in which we can exercise free will during that crucial interval between when we become aware of that action and the action begins: The sum of "what one is" leads one to make a specific decision. Such a decision can occur unconsciously, and initiate an action. However, upon realizing that one is about to perform a specific act, one can consider its likely consequences and the rationales pro and con for performing that act; this information is constructed on the spot, and is not present during unconscious processing.

Libet says we may not have "free will," but we have a "free won't"

And, based on "what one is," one then can decide not to move ahead — or, if the action has begun, one can decide to squelch it (and thus one is not limited to the 200 milliseconds Libet has measured). As Libet notes, we can in fact veto an action, and that decision is not a foregone conclusion. We make decisions for reasons, and those reasons are our reasons.

Libet has made a fundamental discovery. If the timing of mental events is as he describes, then we not only have "free will" in principle — but we also have the opportunity to exercise that free will.

The ideas I've briefly sketched are variants of many others (cf. Kane, 1996), and address issues that have been discussed (sometimes heatedly) for thousands of years. I've not mentioned the issue of "ultimate responsibility"— whether one is completely responsible for "what one is." Given that one cannot control the genetic cards one's parents dealt one, the sense of "free will" developed here seems to go only so far. However, Libet's veto idea leads us to take a step back, and reframe the question: Instead of asking whether one is "ultimately responsible" for every aspect of what one is, why not ask whether one is "proximally responsible" for the effects of every aspect of what one is on what one does? Can we choose — based on what we've chosen to become — to override some impulses and express others?

I hope these brief reflections have conveyed two essential points. The first is that these are extraordinarily knotty issues, and the question of the role of consciousness in free will is not likely to be resolved soon. And the second is that we are entering a new era in discussing such questions. No longer are we restricted to the arm chair and the silver tongue. We now have objective data. This book makes a crucial contribution in providing grist for the mill of anyone interested in consciousness, free will, responsibility, or the relation of mind and body.

(Foreword to Mind Time, by Benjamin Libet, 2002, Harvard U. Press), pp.xii-xv)