Comprehensive compatibilists believe that Free Will can be reconciled with both determinism (as Hume believed) and indeterminism (as many thinkers since William James believe). Comprehensive compatibilists believe that actions are adequately determined by deliberations prior to a decision, including one's character and values, and one's feelings and desires, in short, one's reasons and motives. Their model of free will is "reasons responsive." Comprehensive compatibilists put limits on both determinism and indeterminism. The role of pure chance, irreducible randomness, or quantum indeterminacy, is limited to generating alternative possibilities for action. Chance events are not direct causes of our thoughts and actions, as "radical" libertarians believe. "Soft" - or "Adequate" or "Modest" - Libertarians believe that humans are free from strict physical determinism - or pre-determinism, and all the other diverse forms of determinism. They accept the existence of chance, but believe that if chance were the direct cause of actions, it would preclude control of the agent's actions and deny moral responsibility. Note that for information philosophy and its theory of values, there is a critical separation of the question of free will from questions about moral responsibilty. The existence of free will is a scientific question for physics, biology, and psychology.
Moral responsibility is a cultural question for sociology and the law. Information philosophy also separates responsibility from the ideas of retributive punishment, which is still another social and cultural question.
Libertarians in general believe that determinism and freedom are incompatible. Freedom requires some form of indeterminism. But the two-stage models of free will favored by comprehensive compatibilists also require determination of the action by the agent's motives and reasons, following deliberation and evaluation of the alternative possibilities for action provided by that indeterminism. Critics of libertarianism (both determinists and compatibilists) attack the view of radical libertarians that chance is the direct cause of actions. If an agent's decisions are not connected in any way with character and other personal properties, they rightly claim that the agent can hardly be held responsible for them. Robert Kane's "torn decisions" are an exception to this criticism, because the agent has excellent reasons for acting, whichever way chance takes the ultimate decision. Many determinists and (perhaps most?) compatibilists now accept the idea that there quantum physics requires real indeterminism in the universe. Comprehensive compatibilists can agree with them that if indeterministic chance were the direct direct cause of our actions, that would not be freedom with responsibility. Although any quantum event is probabilistic, quantum processes in macroscopic objects like biological organisms are highhy regular, because of the law of large numbers. Even in microscopic structures like atoms and molecules, it is quantum mechanics that provides the phenomenla stability of such structures over cosmic lifetimes. But determinists and compatibilists might also agree that if chance is not a direct cause of our actions, it would do no harm to responsibility. In which case, comprehensive compatibilists should be able to convince some determinists of their position. Galen Strawson agrees that comprehensive compatibilism is a "kind of freedom that is available" to us.
If chance is limited to providing real alternative possibilities to be considered by the adequately determined will, it provides an intelligible freedom and can explain both freedom and creativity.Comprehensive compatibilists can give the determinists, at least the compatibilists, the kind of freedom they say they want, one that provides an adequately determined will and actions for which we can take responsibility Even the current chief spokesman for libertarianism, Robert Kane admits that "radical" libertarian accounts of free will are unintelligible. No coherent idea can be provided for the role of indeterminism and chance, he says. But Kane doggedly insists that "something more" is needed beyond simple determination of our actions by our desires and feelings, our character and values, and our motives and reasons, that is, given the alternative possibilities that have been generated in the first stage of a two-stage model.
Dennett, D. C. (1978). Brainstorms : philosophical essays on mind and psychology. Montgomery, Vt., Bradford Books. (see "Giving the Libertarians What They Say They Want.")
Kane, R. (2001). The Oxford Handbook of Free Will. Oxford ; New York, Oxford University Press.
1. Clarke, Randolph (2003), Libertarian Accounts of Free Will, p.xiii.
Accounts of free will purport to tell us what is required if we are to be free agents, individuals who, at least sometimes when we act, act freely. Libertarian accounts, of course, include a requirement of indeterminism of one sort or another somewhere in the processes leading to free actions. But while proponents of such views take determinism to preclude free will, indeterminism is widely held to be no more hospitable. An undetermined action, it is said would be random or arbitrary. It could not be rational or rationally explicable. The agent would lack control over her behavior. At best, indeterminism in the processes leading to our actions would be superfluous, adding nothing of value even if it did not detract from what we want.
2. Honderich, Ted (2002), How Free Are You?, p.5.
"Maybe it should have been called determinism-where-it-matters. It allows that there is or may be some indeterminism but only at what is called the micro-level of our existence, the level of the small particles of our bodies."
3. Searle, John (2004), Freedom and Neurobiology, p.74-75.
"First we know that our experiences of free action contain both indeterminism and rationality...Second we know that quantum indeterminacy is the only form of indeterminism that is indisputably established as a fact of nature...it follows that quantum mechanics must enter into the explanation of consciousness."