The question of free will is whether, and in what sense, rational agents exercise control over their actions and decisions. Addressing this question requires understanding the relationship between freedom and cause, and determining whether the laws of nature are causally deterministic. The various philosophical positions taken differ on whether all events are determined or not—determinism versus indeterminism—and also on whether freedom can coexist with determinism or not—compatibilism versus incompatibilism. So, for instance, hard determinists argue that the universe is deterministic, and that this makes free will impossible.
The principle of free will has religious, ethical, and scientific implications. For example, in the religious realm, free will may imply that an omnipotent divinity does not assert its power over individual will and choices. In ethics, it may imply that individuals can be held morally accountable for their actions. In the scientific realm, it may imply that the actions of the body, including the brain and the mind, are not wholly determined by physical causality. The question of free will has been a central issue since the beginning of philosophical thought.
- 1 In Western philosophy
- 2 Moral responsibility
- 3 In science
- 4 In Eastern philosophy
- 5 In other theology
- 6 References
- 7 Further reading
- 8 External links
In Western philosophy
The basic philosophical positions on the problem of free will can be divided in accordance with the answers they provide to two questions:
- Is determinism true? and
- Does free will exist?
Determinism is roughly defined as the view that all current and future events are necessitated by past events combined with the laws of nature. According to McKenna (2004), neither determinism nor its opposite, non-determinism, are positions in the debate about free will.("Compatibilism", The Stanford Encyclopedia of Philosophy (Summer 2004 Edition), Edward N. Zalta (ed.),)
Compatibilism is the view that the existence of free will and the truth of determinism are compatible with each other; this is opposed to incompatibilism which is the view that there is no way to reconcile a belief in a deterministic universe with a belief in free will.<ref>Ginet, C. 1983. "In Defense of Incompatibilism" in Philosophical Studies 44, pp. 391–400</ref> Hard determinism is the version of incompatibilism that accepts the truth of determinism and rejects the idea that humans have any free will.<ref>Koons, J.R. "Is Hard Determinism a Form of Compatibilism?" in The Philosophical Forum. 33:1</ref> Metaphysical libertarianism topically agrees with hard determinism only in rejecting compatibilism. Because libertarians accept the existence of free will, they must reject determinism and argue for some version of indeterminism that is compatible with freedom. 
Causal (or nomological) determinism is the thesis that future events are necessitated by past and present events combined with the laws of nature. Such determinism is sometimes illustrated by the thought experiment of Laplace's demon. Imagine an entity that knows all facts about the past and the present, and knows all natural laws that govern the universe. Such an entity may be able to use this knowledge to foresee the future, down to the smallest detail.
Logical determinism is the notion that all propositions, whether about the past, present or future, are either true or false. The problem of free will, in this context, is the problem of how choices can be free, given that what one does in the future is already determined as true or false in the present.
Theological determinism is the thesis that there is a God who determines all that humans will do, either by knowing their actions in advance, via some form of omniscience (God, Foreknowledge and Freedom. Stanford, CA: Stanford University Press. ISBN 1-55786-857-3) or by decreeing their actions in advance. The problem of free will, in this context, is the problem of how our actions can be free, if there is a being who has determined them for us ahead of time.
Biological determinism is the idea that all behavior, belief, and desire are fixed by our genetic endowment. There are other theses on determinism, including cultural determinism and psychological determinism.<ref name="Viv" /> Combinations and syntheses of determinist theses, e.g. bio-environmental determinism, are even more common.
Compatibilists maintain that determinism is compatible with free will. A common strategy employed by "classical compatibilists", such as Thomas Hobbes, is to claim that a person acts freely only when the person willed the act and the person could have done otherwise, if the person had decided to. Hobbes sometimes attributes such compatibilist freedom to the person and not to some abstract notion of will, asserting, for example, that "no liberty can be inferred to the will, desire, or inclination, but the liberty of the man; which consisteth in this, that he finds no stop, in doing what he has the will, desire, or inclination to doe" In articulating this crucial proviso, David Hume writes, "this hypothetical liberty is universally allowed to belong to every one who is not a prisoner and in chains".( A Treatise of Human Nature 1967 edition).
To illustrate their position, compatibilists point to clear-cut cases of someone's free will being denied, through rape, murder, theft, or other forms of constraint. In these cases, free will is lacking not because the past is causally determining the future, but because the aggressor is overriding the victim's desires and preferences about his own actions. The aggressor is coercing the victim and, according to compatibilists, this is what overrides free will. Thus, they argue that determinism does not matter; what matters is that individuals' choices are the results of their own desires and preferences, and are not overridden by some external (or internal) force. To be a compatibilist, one need not endorse any particular conception of free will, but only deny that determinism is at odds with free will.<
William James's views were ambivalent. While he believed in free will on "ethical grounds," he did not believe that there was evidence for it on scientific grounds, nor did his own introspections support it. Moreover, he did not accept incompatibilism as formulated below; he did not believe that the indeterminism of human actions was a prerequisite of moral responsibility. In his work Pragmatism, he wrote that "instinct and utility between them can safely be trusted to carry on the social business of punishment and praise" regardless of metaphysical theories. He did believe that indeterminism is important as a "doctrine of relief", - it allows for the view that, although the world may be in many respects a bad place, it may, through individuals' actions, become a better one. Determinism, he argued, undermines meliorism—the idea that progress is a real concept leading to improvement in the world.
"Modern compatibilists", such as Harry Frankfurt and Daniel Dennett, argue that there are cases where a coerced agent's choices are still free because such coercion coincides with the agent's personal intentions and desires Freedom of the Will and the Concept of the Person in "Journal of Philosophy" Elbow Room: The Varieties of Free Will Worth Wanting. Bradford Books. ISBN 0-262-54042-8) Frankfurt, in particular, argues for a version of compatibilism called the "hierarchical mesh". The idea is that an individual can have conflicting desires at a first-order level and also have a desire about the various first-order desires (a second-order desire) to the effect that one of the desires prevails over the others. A person's will is to be identified with her effective first-order desire, i.e., the one that she acts on. So, for example, there are "wanton addicts", "unwilling addicts" and "willing addicts." All three groups may have the conflicting first-order desires to want to take the drug to which they are addicted and to not want to take it.
The first group, "wanton addicts", have no second-order desire not to take the drug. The second group, "unwilling addicts", have a second-order desire not to take the drug, while the third group, "willing addicts", have a second-order desire to take it. According to Frankfurt, the members of the first group are to be considered devoid of will and therefore no longer persons. The members of the second group freely desire not to take the drug, but their will is overcome by the addiction. Finally, the members of the third group willingly take the drug to which they are addicted. Frankfurt's theory can ramify to any number of levels. Critics of the theory point out that there is no certainty that conflicts will not arise even at the higher-order levels of desire and preference.
In Elbow Room, Dennett presents an argument for a compatibilist theory of free will, which he further elaborated in the book Freedom Evolves. The basic reasoning is that, if one excludes God, an infinitely powerful demon, and other such possibilities, then because of chaos and epistemic limits on the precision of our knowledge of the current state of the world, the future is ill-defined for all finite beings. The only well-defined things are "expectations". The ability to do "otherwise" only makes sense when dealing with these expectations, and not with some unknown and unknowable future.
According to Dennett, because individuals have the ability to act differently from what anyone expects, free will can exist.<ref name="DD2" /> Incompatibilists claim the problem with this idea is that we may be mere "automata responding in predictable ways to stimuli in our environment". Therefore, all of our actions are controlled by forces outside ourselves, or by random chance. More sophisticated analyses of compatibilist free will have been offered, as have other critiques.<ref name="CompSEP" />
"Hard determinists", such as d'Holbach, are those incompatibilists who accept determinism and reject free will. "Metaphysical libertarians", such as Thomas Reid, Peter van Inwagen, and Robert Kane, are those incompatibilists who accept free will and deny determinism, holding the view that some form of indeterminism is true. Another view is that of hard incompatibilism which states that free will is incompatible with both determinism and indeterminism. This view is defended by Derk Pereboom.
One of the traditional arguments for incompatibilism is based on an "intuition pump": if a person is determined in his or her choices of actions, then he or she must be like other mechanical things that are determined in their behavior such as a wind-up toy, a billiard ball, a puppet, or a robot. Because these things have no free will, then people must have no free will, if determinism is true. This argument has been rejected by compatibilists such as Daniel Dennett on the grounds that, even if humans have something in common with these things, it does not follow that there are no important differences.
Another argument for incompatibilism is that of the "causal chain." Incompatibilism is key to the idealist theory of free will. Most incompatibilists reject the idea that freedom of action consists simply in "voluntary" behavior. They insist, rather, that free will means that man must be the "ultimate" or "originating" cause of his actions. He must be a causa sui, in the traditional phrase. To be responsible for one's choices is to be the first cause of those choices, where first cause means that there is no antecedent cause of that cause. The argument, then, is that if man has free will, then man is the ultimate cause of his actions. If determinism is true, then all of man's choices are caused by events and facts outside his control. So, if everything man does is caused by events and facts outside his control, then he cannot be the ultimate cause of his actions. Therefore, he cannot have free will.
A third argument for incompatibilism was formulated by Carl Ginet in the 1960s and has received much attention in the modern literature. The simplified argument runs along these lines: if determinism is true, then we have no control over the events of the past that determined our present state and no control over the laws of nature. Since we can have no control over these matters, we also can have no control over the consequences of them. Since our present choices and acts, under determinism, are the necessary consequences of the past and the laws of nature, then we have no control over them and, hence, no free will. This is called the consequence argument.
The difficulty of this argument for compatibilists lies in the fact that it entails the impossibility that one could have chosen other than one has. For example, if Jane is a compatibilist and she has just sat down on the sofa, then she is committed to the claim that she could have remained standing, if she had so desired. But it follows from the consequence argument that, if Jane had remained standing, she would have either generated a contradiction, violated the laws of nature or changed the past. Hence, compatibilists are committed to the existence of "incredible abilities", according to Ginet and van Inwagen. One response to this argument is that it equivocates on the notions of abilities and necessities, or that the free will evoked to make any given choice is really an illusion and the choice had been made all along, oblivious to its "decider".
The other view under the heading of incompatiblism is metaphysical libertarianism. Libertarianism holds that free-will exists, which entails that the individual is able to take more than one possible course of actions under a given set of circumstances. Since determinism implies that there is only one possible future, it is not compatible with this conception of free-will, and must be false.
Accounts of libertarianism subdivide into supernatural theories and scientific or naturalistic theories. Supernatural theories hold that a non-physical mind or soul overrides physical causality, so that physical events in the brain that lead to the performance of actions do not have an entirely physical explanation. This approach is allied to mind-body dualism, and sometimes has a theological motivation.
Scientific explanations of libertarianism (described as "naturalistic") sometimes involve invoking panpsychism, the theory that a quality of mind is associated with all particles, and pervades the entire universe, in both sentient and non-sentient entities. . Other naturalistic approaches do not require free will to be a fundamental constituent of the universe; ordinary randomness is appealed to as supplying the "elbow room" believed to be necessary by libertarians. Free volition is regarded as a particular kind of complex, high-level process with an element of indeterminism. An example of this kind of approach has been developed by Robert Kane.
Some philosophers' views are difficult to categorize as either compatibilist or incompatibilist, hard determinist or libertarian. John Locke, for example, denied that the phrase "free will" made any sense (compare with theological noncognitivism, a similar stance on the existence of God). He also took the view that the truth of determinism was irrelevant. He believed that the defining feature of voluntary behavior was that individuals have the ability to postpone a decision long enough to reflect or deliberate upon the consequences of a choice: "...the will in truth, signifies nothing but a power, or ability, to prefer or choose". Similarly, David Hume discussed the possibility that the entire debate about free will is nothing more than a merely "verbal" issue. He also suggested that it might be accounted for by "a false sensation or seeming experience" (a velleity) which is associated with many of our actions when we perform them. On reflection, we realize that they were necessary and determined all along.
Arthur Schopenhauer put the puzzle of free will and moral responsibility in these terms:
Everyone believes himself a priori to be perfectly free, even in his individual actions, and thinks that at every moment he can commence another manner of life. ... But a posteriori, through experience, he finds to his astonishment that he is not free, but subjected to necessity, that in spite of all his resolutions and reflections he does not change his conduct, and that from the beginning of his life to the end of it, he must carry out the very character which he himself condemns...."<ref>Schopenhauer, Arthur, The Wisdom of Life, p 147</ref>
In his On the Freedom of the Will, Schopenhauer stated, "You can do what you will, but in any given moment of your life you can will only one definite thing and absolutely nothing other than that one thing."
Rudolf Steiner, who collaborated in a complete edition of Arthur Schopenhauer's work (http://www.pitt.edu/~kafka/k_s_bibII.html], wrote The Philosophy of Freedom, which focuses on the problem of free will. Steiner (1861–1925) initially divides this into the two aspects of freedom: freedom of thought and freedom of action. He argues that inner freedom is achieved when we bridge the gap between our sensory impressions, which reflect the outer appearance of the world, and our thoughts, which give us access to the inner nature of the world. Outer freedom is attained by permeating our deeds with moral imagination. Steiner aims to show that these two aspects of inner and outer freedom are integral to one another, and that true freedom is only achieved when they are united. 
The contemporary philosopher Galen Strawson agrees with Locke that the truth or falsity of determinism is irrelevant to the problem. He argues that the notion of free will leads to an infinite regress and is therefore senseless. According to Strawson, if one is responsible for what one does in a given situation, then one must be responsible for the way one is in certain mental respects. But it is impossible for one to be responsible for the way one is in any respect. This is because in order to be responsible for the way one is in some situation "S", one must have been responsible for the way one was at "S-1". In order to be responsible for the way one was at "S-1", one must have been responsible for the way one was at "S-2", and so on. At some point in the chain, there must have been an act of origination of a new causal chain. But this is impossible. Man cannot create himself or his mental states ex nihilo. This argument entails that free will itself is absurd, but not that it is incompatible with determinism. Strawson calls his own view "pessimism" but it can be classified as hard incompatibilism.
Ted Honderich holds the view that "determinism is true, compatibilism and incompatibilism are both false" and the real problem lies elsewhere. Honderich maintains that determinism is true because quantum phenomena are not events or things that can be located in space and time, but are abstract entities. Further, even if they were micro-level events, they do not seem to have any relevance to how the world is at the macroscopic level. He maintains that incompatibilism is false because, even if determinism is true, incompatibilists have not, and cannot, provide an adequate account of origination. He rejects compatibilism because it, like incompatibilism, assumes a single, fundamental notion of freedom. There are really two notions of freedom: voluntary action and origination. Both notions are needed in order to explain freedom of will and responsibility. Both determinism and indeterminism are threats to such freedom. To abandon these notions of freedom would be to abandon moral responsibility. On the one side, we have our intuitions; on the other, the scientific facts. The "new" problem is how to resolve this conflict.
Society generally holds people responsible for their actions, and will say that they deserve praise or blame for what they do. However, many believe that moral responsibility requires free will. Thus, another important issue in the debate on free will is whether individuals are ever morally responsible for their actions—and, if so, in what sense.
Incompatibilists tend to think that determinism is at odds with moral responsibility. It seems impossible that one can hold someone responsible for an action that could be predicted from (potentially) the beginning of time. Hard determinists say "So much the worse for free will!" and discard the concept.<ref name="Ben1">Benditt, Theodore (1998) Philosophy Then and Now with eds. Arnold and Graham. Oxford: Blackwell Publishing, 1998. ISBN 1-55786-742-9</ref> Clarence Darrow, the famous defense attorney, pleaded the innocence of his clients, Leopold and Loeb, by invoking such a notion of hard determinism.<ref name="Darrow">Darrow, Clarence, 1924, “The Plea of Clarence Darrow, in Defense of Richard Loeb and Nathan Leopold, Jr., On Trial for Murder” page reference is to the reprint in Philosophical Explorations: Freedom, God, and Goodness, S. Cahn (ed.), New York: Prometheus Books, 1989.</ref> During his summation, he declared:
What has this boy to do with it? He was not his own father; he was not his own mother; he was not his own grandparents. All of this was handed to him. He did not surround himself with governesses and wealth. He did not make himself. And yet he is to be compelled to pay.<ref name="Darrow" />
Conversely, libertarians say "So much the worse for determinism!"<ref name="Ben1" /> Daniel Dennett asks why anyone would care about whether someone had the property of responsibility and speculates that the idea of moral responsibility may be "a purely metaphysical hankering".<ref name="DD1" /> Jean-Paul Sartre argues that people sometimes avoid incrimination and responsibility by hiding behind determinism: "... we are always ready to take refuge in a belief in determinism if this freedom weighs upon us or if we need an excuse".<ref name="Sartre2">Sartre, J.P. (1943) Being and Nothingness, reprint 1993. New York:Washington Square Press.</ref> However, the position that classifying such people as "base" or "dishonest" makes no difference to whether or not their actions are determined is quite as tenable.
The issue of moral responsibility is at the heart of the dispute between hard determinists and compatibilists. Hard determinists are forced to accept that individuals often have "free will" in the compatibilist sense, but they deny that this sense of free will can ground moral responsibility. The fact that an agent's choices are unforced, hard determinists claim, does not change the fact that determinism robs the agent of responsibility.
Compatibilists argue, on the contrary, that determinism is a prerequisite for moral responsibility. Society cannot hold someone responsible unless his actions were determined by something. This argument can be traced back to David Hume. If indeterminism is true, then those events that are not determined are random. It is doubtful that one can praise or blame someone for performing an action generated spontaneously by his nervous system. Instead, one needs to show how the action stemmed from the person's desires and preferences—the person's character—before one can hold the person morally responsible.<ref name="Hume" /> Libertarians may reply that undetermined actions are not random at all, and that they result from a substantive will whose decisions are undetermined. This argument is considered unsatisfactory by compatibilists, for it just pushes the problem back a step. It also seems to involve some mysterious metaphysics, as well as the concept of ex nihilo nihil fit. Libertarians have responded by trying to clarify how undetermined will could be tied to robust agency.<ref name="Oconnor"> O'Connor, Timothy ed. Agents, Causes, & Event: Essays on Indeterminism and Free Will, 1995 Oxford University Press.</ref>
St. Paul, in his Epistle to the Romans addresses the question of moral responsibility as follows: "Hath not the potter power over the clay, of the same lump to make one vessel unto honour, and another unto dishonour?"<ref>St. Paul, "Epistle to the Romans", 9:21, King James Bible Tennessee:The Gideons International</ref> In this view, individuals can still be dishonoured for their acts even though those acts were ultimately completely determined by God.
A similar view has it that individual moral culpability lies in individual character. That is, a person with the character of a murderer has no choice other than to murder, but can still be punished because it is right to punish those of bad character. How one's character was determined is irrelevant from this perspective. Hence, Robert Cummins and others argue that people should not be judged for their individual actions, but rather for how those actions "reflect on their character". If character (however defined) is the dominant causal factor in determining one's choices, and one's choices are morally wrong, then one should be held accountable for those choices, regardless of genes and other such factors.<ref>Vuoso, G. (1987) "Background Responsibility and Excuse," Yale Law Journal, 96, pp. 1680–81</ref><ref>Cummins, R. "Culpability" and Mental Disorder", p. 244</ref>
One exception to the assumption that moral culpability lies in either individual character or freely willed acts is in cases where the insanity defense—or its corollary, diminished responsibility—can be used to argue that the guilty deed was not the product of a guilty mind.<ref name = "Goldstein">Goldstein, A. M., Morse, S. J. & Shapiro, D. L. 2003 "Evaluation of criminal responsibility". In Forensic psychology. vol. 11 (ed. A. M. Goldstein), pp. 381–406. New York: Wiley.</ref> In such cases, the legal systems of most Western societies assume that the person is in some way not at fault, because his actions were a consequence of abnormal brain function.
Joshua Greene and Jonathan Cohen, researchers in the emerging field of neuroethics, argue, on the basis of such cases, that our current notion of moral responsibility is founded on libertarian (and dualist) intuitions.<ref name="Greene">Greene, J. Cohen, J. (2004). "For the law, neuroscience changes nothing and everything". Philosophical Transactions of the Royal Society of London B, 359, 1775–1785.</ref> They argue that cognitive neuroscience research is undermining these intuitions by showing that the brain is responsible for our actions, not only in cases of florid psychosis, but even in less obvious situations. For example, damage to the frontal lobe reduces the ability to weigh uncertain risks and make prudent decisions, and therefore leads to an increased likelihood that someone will commit a violent crime.<ref name = "Brower"> Brower M.C. and Price B.H. (2001). "Neuropsychiatry of frontal lobe dysfunction in violent and criminal behaviour: a critical review". Journal of Neurology, Neurosurgery and Psychiatry, 71: 720–726.</ref> This is true not only of patients with damage to the frontal lobe due to accident or stroke, but also of adolescents, who show reduced frontal lobe activity compared to adults,<ref name = "SteinScott">Steinberg, L., Scott, E. S. (2003). "Less guilty by reason of adolescence: developmental immaturity, diminished responsibility, and the juvenile death penalty". American Psychologist 58, 1009–1018. </ref> and even of children who are chronically neglected or mistreated.<ref name = "TAPANK">Teicher, M. H., Anderson, S. L., Polcari, A., Anderson, C. M., Navalta, C. P., and Kim, D. M. (2003). "The neurobiological consequences of early stress and childhood maltreatment". Neuroscience and Behavioral Reviews, 27: 33–44.</ref> In each case, the guilty party can be said to have less responsibility for his actions.<ref name="Greene" /> Greene and Cohen predict that, as such examples become more common and well known, jurors’ interpretations of free will and moral responsibility will move away from the intuitive libertarian notion which currently underpins them.
Greene and Cohen also argue that the legal system does not require this libertarian interpretation. Rather, they suggest that only retributive notions of justice, in which the goal of the legal system is to punish people for misdeeds, require the libertarian intuition. Consequentialist approaches to justice, which are aimed at promoting future welfare rather than meting out just deserts, can survive even a hard determinist interpretation of free will. Accordingly, the legal system and notions of justice can thus be maintained even in the face of emerging neuroscientific evidence undermining libertarian intuitions of free will.
Many, but not all, arguments for or against free will make an assumption about the truth or falsehood of determinism. The scientific method holds out the promise of being able to turn such assumptions into fact. However, such facts would still need to be combined with philosophical considerations in order to amount to an argument for or against free will. For instance, if compatibilism is true, the truth of determinism would have no effect on the question of the existence of free will. On the other hand, a proof of determinism in conjunction with an argument for incompatibilism would add up to an argument against free will.
Early scientific thought often portrayed the universe as deterministic,<ref> for example in the thought of Democritus or the Cārvākans</ref> and some thinkers claimed that the simple process of gathering sufficient information would allow them to predict future events with perfect accuracy. Modern science, on the other hand, is a mixture of deterministic and stochastic theories.<ref>Boniolo, G. and Vidali, P. (1999) Filosofia della Scienza, Milan: Mondadori. ISBN 88-424-9359-7</ref> Quantum mechanics predicts events only in terms of probabilities, casting doubt on whether the universe is deterministic at all. The possibility that the universe at the macroscopic level may be governed by indeterministic laws, as it is generally accepted to be at the quantum level, has revived interest in free will among physicists.<ref>Davies, P. Chaos Frees the Universe</ref> However, there are a number of objections.
It is claimed by some that quantum indeterminism is confined to microscopic phenomena.<ref>Honderich, E. Determinism as True, Compatibilism and Incompatibilism as Both False, and the Real Problem</ref> The claim that events at the atomic or particulate level are unknowable can be challenged experimentally and even technologically: for instance, some hardware random number generators work by amplifying quantum effects into practically usable signals. However, this only amounts to macroscopic indeterminism if it can be shown that microscopic events really are indeterministic.
This consideration leads to the criticism of indeterminism-based free will on the basis that quantum mechanics is not really random, but merely unpredictable. Some scientific determinists, following Albert Einstein, believe in so-called "hidden variable theories" according to which the unpredictability of quantum mechanics is due to ignorance of an additional set of physical variables not explicitly included in the standard theory (see the Bohm interpretation and the EPR paradox).<ref name="GG">Ghirardi, G. (1997) Un' Occhiata alle Carte di Dio. Milan:Il Saggiatore. ISBN 88-428-0947-0</ref>
There is also a further, more philosophical, objection. It has been argued that if an action is taken due to quantum randomness, this in itself means that free will is absent, since such action cannot be controllable by someone claiming to possess such free will.<ref>Reason Online. Freedom Evolves</ref> If this argument is conjoined with incompatibilism, then it would follow that free will is impossible, since it would be incompatible with both determinism and indeterminism, and these are the only options. If it is conjoined with compatibilism, on the other hand, it would mean that free will is only possible in a deterministic universe.
Robert Kane has capitalized on the success of quantum mechanics and chaos theory in order to defend incompatibilist freedom in his The Significance of Free Will and other writings.<ref>Kane, Robert. 1996b. The Significance of Free Will. New York: Oxford University Press. ISBN 0-19-512656-4</ref>
Like physicists, biologists have frequently addressed questions related to free will. One of the most heated debates in biology is that of "nature versus nurture", concerning the relative importance of genetics and biology as compared to culture and environment in human behavior.<ref name="Pin">Pinel, P.J. (1990) Biopsychology. Prentice Hall Inc. ISBN 88-15-07174-1</ref> The view of most researchers is that many human behaviors can be explained in terms of humans' brains, genes, and evolutionary histories.<ref>DeFries, J. C., McGuffin, P., McClearn, G. E., Plomin, R. (2000) Behavioral Genetics 4th ED. W H Freeman & Co.</ref><ref>Morris, D. (1967) The Naked Ape. New York:McGraw-Hill. ISBN 0-385-33430-3</ref><ref name="Dawk">Dawkins, R. (1976) The Selfish Gene. Oxford:Oxford University Press. ISBN 88-04-39318-1</ref> This point of view raises the fear that such attribution makes it impossible to hold others responsible for their actions. Steven Pinker's view is that fear of determinism in the context of "genetics" and "evolution" is a mistake, that it is "a confusion of explanation with exculpation". Responsibility doesn't require behavior to be uncaused, as long as behaviour responds to praise and blame.<ref name="Pink">Pinker, S.(2002) The Blank Slate: The Modern Denial of Human Nature. London:Penguin. p.179 ISBN 0-14-200334-4</ref> Moreover, it is not certain that environmental determination is any less threatening to free will than genetic determination.<ref name="Lew">Lewontin, R. (2000)It Ain't Necessarily So:The Dream of the Human Genome and other Illusions. New York:NYREV Inc. ISBN 88-420-6418-1</ref>
It has become possible to study the living brain, and researchers can now watch the brain's decision-making "machinery" at work. A seminal experiment in this field was conducted by Benjamin Libet in the 1980s, in which he asked each subject to choose a random moment to flick her wrist while he measured the associated activity in her brain (in particular, the build-up of electrical signal called the readiness potential). Although it was well known that the readiness potential preceded the physical action, Libet asked whether the readiness potential corresponded to the felt intention to move. To determine when the subject felt the intention to move, he asked her to watch the second hand of a clock and report its position when she felt that she had the conscious will to move.<ref name="LGW"> Libet, B., Gleason, C.A., Wright, E.W., Pearl, D.K. (1983). Time of conscious intention to act in relation to onset of cerebral activity (readiness-potential). The unconscious initiation of a freely voluntary act. Brain. 106 (3):623–642. PMID 6640273</ref>
Libet found that the unconscious brain activity leading up to the conscious decision by the subject to flick his or her wrist began approximately half a second before the subject consciously felt that she had decided to move.<ref name="LGW" /><ref>Libet, B. (1985) Unconscious cerebral initiative and the role of conscious will in voluntary action. Behavioral and Brain Sciences, 8: 529–566.</ref> Libet's findings suggest that decisions made by a subject are first being made on a subconscious level and only afterward being translated into a "conscious decision", and that the subject's belief that it occurred at the behest of her will was only due to her retrospective perspective on the event. The interpretation of these findings has been criticized by Daniel Dennett, who argues that people will have to shift their attention from their intention to the clock, and that this introduces temporal mismatches between the felt experience of will and the perceived position of the clock hand.<ref>Dennett, D. (1991) Consciousness Explained. The Penguin Press. ISBN 0-7139-9037-6 (UK Hardcover edition, 1992) ISBN 0-316-18066-1 (paperback)</ref><ref> Dennett, Daniel C and Marcel, Kinsbourne (1992)Time and the Observer. Behavioral and Brain Sciences 15(2), 183–247. </ref> Consistent with this argument, subsequent studies have shown that the exact numerical value varies depending on attention.<ref name="HandE">Haggard, P. and Eimer, M. (1999). On the relation between brain potentials and the awareness of voluntary movements. Experimental Brain Research 126, 128–133. PMID 10333013</ref><ref> Trevena, J.A. and Miller, J. (2002). Cortical movement preparation before and after a conscious decision to move. Consciousness and Cognition 11, 162–190. PMID 12191935 </ref> Despite the differences in the exact numerical value, however, the main finding has held.<ref>Haggard, P. (2005). Conscious intention and motor cognition. Trends in Cognitive Sciences 9, 6 : 290–295. PMID 15925808</ref>
In a variation of this task, Haggard and Eimer asked subjects to decide not only when to move their hands, but also to decide which hand to move. In this case, the felt intention correlated much more closely with the "lateralized readiness potential" (LRP), an EEG component which measures the difference between left and right hemisphere brain activity. Haggard and Eimer argue that the feeling of conscious will therefore must follow the decision of which hand to move, since the LRP reflects the decision to lift a particular hand.<ref name="HandE" />
Related experiments showed that neurostimulation could affect which hands people move, even though the experience of free will was intact. Ammon and Gandevia found that it was possible to influence which hand people move by stimulating frontal regions that are involved in movement planning using transcranial magnetic stimulation in either the left or right hemisphere of the brain.<ref>Ammon, K. and Gandevia, S.C. (1990) Transcranial magnetic stimulation can influence the selection of motor programmes. Journal of Neurology, Neurosurgery and Psychiatry 53: 705–707. PMID 2213050</ref> Right-handed people would normally choose to move their right hand 60% of the time, but when the right hemisphere was stimulated they would instead choose their left hand 80% of the time (recall that the right hemisphere of the brain is responsible for the left side of the body, and the left hemisphere for the right). Despite the external influence on their decision-making, the subjects continued to report that they believed their choice of hand had been made freely. In a follow-up experiment, Alvaro Pascual-Leone and colleagues found similar results, but also noted that the transcranial magnetic stimulation must occur within 200 milliseconds, consistent with the time-course derived from the Libet experiments.<ref> Brasil-Neto, J.P., Pascual-Leone, A., Valls-Solé, J., Cohen, L.G. and Hallett, M. (1992) Focal transcranial magnetic stimulation and response bias in a forced-choice task. Journal of Neurology, Neurosurgery and Psychiatry 55: 964–966. PMID 1431962</ref>
Despite these findings, Libet himself does not interpret his experiment as evidence of the inefficacy of conscious free will—he points out that although the tendency to press a button may be building up for 500 milliseconds, the conscious will retains a right to veto that action in the last few milliseconds.<ref>Libet, (2003). "Can Conscious Experience affect brain Activity?", Journal of Consciousness Studies 10, nr. 12, pp 24–28.</ref> According to this model, unconscious impulses to perform a volitional act are open to suppression by the conscious efforts of the subject (sometimes referred to as "free won't"). A comparison is made with a golfer, who may swing a club several times before striking the ball. The action simply gets a rubber stamp of approval at the last millisecond. Max Velmans argues however that "free won't" may turn out to need as much neural preparation as "free will".<ref>Velmans, M. (2003) "Preconscious free will", Journal of Consciousness Studies 10, nr. 12, pp 42–61.</ref>
Neurology and psychiatry
There are several brain-related conditions in which an individual's actions are not felt to be entirely under his or her control. Although the existence of such conditions does not directly refute the existence of free will, the study of such conditions, like the neuroscientific studies above, is valuable in developing models of how the brain may construct our experience of free will.
For example, people with Tourette syndrome and related tic disorders make involuntary movements and utterances, called tics, despite the fact that they would prefer not to do so when it is socially inappropriate. Tics are described as semi-voluntary or "unvoluntary",<ref name=TSADef>Tourette Syndrome Association. Definitions and Classification of Tic Disorders. Accessed 19 Aug 2006.</ref> because they are not strictly involuntary: they may be experienced as a voluntary response to an unwanted, premonitory urge. Tics are experienced as irresistible and must eventually be expressed.<ref name=TSADef/> People with Tourette syndrome are sometimes able to suppress their tics to some extent for limited periods, but doing so often results in an explosion of tics afterward. The control which can be exerted (from seconds to hours at a time) may merely postpone and exacerbate the ultimate expression of the tic.<ref name=Zinner>Zinner S.H. (2000) Tourette disorder. Pediatric Review, 21(11):372. PMID 11077021</ref>
In alien hand syndrome, the afflicted individual's limb will produce meaningful behaviours without the intention of the subject. The clinical definition requires "feeling that one limb is foreign or has a will of its own, together with observable involuntary motor activity" (emphasis in original).<ref name=Doody>Doody RS, Jankovic J. (1992). The alien hand and related signs. Journal of Neurology, Neurosurgery and Psychiatry, 55:806–810. PMID 1402972</ref> This syndrome is often a result of damage to the corpus callosum, either when it is severed to treat intractable epilepsy or due to a stroke. The standard neurological explanation is that the felt will reported by the speaking left hemisphere does not correspond with the actions performed by the non-speaking right hemisphere, thus suggesting that the two hemispheres may have independent senses of will.<ref name=Scepkowski>Scepkowski, L.A., & Cronin-Golomb, A. (2003). The alien hand: cases, categorizations, and anatomical correlates. Behavioral and Cognitive Neuroscience Reviews, 2(4):261–277. PMID 15006289</ref><ref name=Bundick>Bundick, T., Spinella, M. (2000). Subjective experience, involuntary movement, and posterior alien hand syndrome. Journal of Neurology, Neurosurgery and Psychiatry, 68:83–85 PMID 10601408</ref>
Similarly, one of the most important ("first rank") diagnostic symptoms of schizophrenia is the delusion of being controlled by an external force.<ref name=Schneider>Schneider, K. (1959). Clinical Psychopathology. New York: Grune and Stratton. </ref> People with schizophrenia will sometimes report that, although they are acting in the world, they did not initiate, or will, the particular actions they performed. This is sometimes likened to being a robot controlled by someone else. Although the neural mechanisms of schizophrenia are not yet clear, one influential hypothesis is that there is a breakdown in brain systems that compare motor commands with the feedback received from the body (known as proprioception), leading to attendant hallucinations and delusions of control.<ref name=frith>Frith CD, Blakemore S, Wolpert DM. (2000). Explaining the symptoms of schizophrenia: abnormalities in the awareness of action. Brain Brain Research Reviews. 2000 Mar;31(2-3):357-63. PMID 10719163</ref>
Also, obsessive-compulsive disorder and other compulsive behaviour, such as compulsive overeating and addiction, may be linked to a lack of free will. And only hints, or degrees, of this may be linked to a lack of totally free will.
Determinism and emergent behaviour
In generative philosophy of cognitive sciences and evolutionary psychology, free will is assumed not to exist.<ref name= "Kenrick">Kenrick, D. T., Li, N. P., & Butner, J. (2003). "Dynamical evolutionary psychology: Individual decision rules and emergent social norms." Psychological Review, 2003 Jan;110(1):3–28. PMID 12529056</ref><ref name="Epstein">Epstein J.M. and Axtell R. (1996) Growing Artificial Societies - Social Science from the Bottom. Cambridge MA, MIT Press.</ref> However, an illusion of free will is created, within this theoretical context, due to the generation of infinite or computationally complex behaviour from the interaction of a finite set of rules and parameters. Thus, the unpredictability of the emerging behaviour from deterministic processes leads to a perception of free will, even though free will as an ontological entity is assumed not to exist.<ref name="Kenrick" /><ref name= "Epstein" /> In this picture, even if the behavior could be computed ahead of time, no way of doing so will be simpler than just observing the outcome of the brain's own computations.<ref name ="wolfram"> Wolfram, Stephen, A New Kind of Science. Wolfram Media, Inc., May 14, 2002. ISBN 1-57955-008-8 </ref>
As an illustration, some strategy board games have rigorous rules in which no information (such as cards' face values) is hidden from either player and no random events (such as dice rolling) occur in the game. Nevertheless, strategy games like chess and especially Go, with its simple deterministic rules, can have an extremely large number of unpredictable moves. By analogy, "emergentists" suggest that the experience of free will emerges from the interaction of finite rules and deterministic parameters that generate infinite and unpredictable behaviour. Yet, if all these events were accounted for, and there were a known way to evaluate these events, the seemingly unpredictable behavior would become predictable.<ref name= "Kenrick">Kenrick, D. T., Li, N. P., & Butner, J. 2003; Nowak A., Vallacher R.R., Tesser A., Borkowski W., 2000</ref><ref name= "Epstein">Epstein J.M. and Axtell R. 1996; Epstein J.M. 1999</ref>
Experimental psychology's contributions to the free will debate have come primarily through social psychologist Daniel Wegner's work on conscious will. In his book, The Illusion of Conscious Will<ref name = "WegnerBook">Wegner, D.M. (2002). The illusion of conscious will. Cambridge, MA: MIT Press.</ref> Wegner summarizes empirical evidence supporting the view that human perception of conscious control is an illusion. Wegner observes that one event is inferred to have caused a second event when two requirements are met:
- The first event immediately precedes the second event, and
- The first event is consistent with having caused the second event.
For example, if a person hears an explosion and sees a tree fall down that person is likely to infer that the explosion caused the tree to fall over. However, if the explosion occurs after the tree falls down (i.e., the first requirement is not met), or rather than an explosion, the person hears the ring of a telephone (i.e., the second requirement is not met), then that person is not likely to infer that either noise caused the tree to fall down.
Wegner has applied this principle to the inferences people make about their own conscious will. People typically experience a thought that is consistent with a behavior, and then they observe themselves performing this behavior. As a result, people infer that their thoughts must have caused the observed behavior. However, Wegner has been able to manipulate people's thoughts and behaviors so as to conform to or violate the two requirements for causal inference.<ref name ="WegnerBook" /><ref>Wegner, D.M. & Wheatley, T. (1999). Apparent mental causation: sources of the experience of will. American Psychologist, 54, 480-491.</ref> Through such work, Wegner has been able to show that people will often experience conscious will over behaviors that they have in fact not caused, and conversely, that people can be led to experience a lack of will over behaviors that they did cause. The implication for such work is that the perception of conscious will is not tethered to the execution of actual behaviors. Although many interpret this work as a blow against the argument for free will, Wegner has asserted that his work informs only of the mechanism for perceptions of control, not for control itself.
In Eastern philosophy
In Hindu philosophy
The six orthodox (astika) schools of thought in Hindu philosophy do not agree with each other entirely on the question of free will. For the Samkhya, for instance, matter is without any freedom, and soul lacks any ability to control the unfolding of matter. The only real freedom (kaivalya) consists in realizing the ultimate separateness of matter and self. For the Yoga school, only Ishvara is truly free, and its freedom is also distinct from all feelings, thoughts, actions, or wills, and is thus not at all a freedom of will. The metaphysics of the Nyaya and Vaisheshika schools strongly suggest a belief in determinism, but do not seem to make explicit claims about determinism or free will.<ref name ="koller">Koller, J. (2007) Asian Philosophies. 5th ed. Prentice Hall. ISBN 0-13-092385-0</ref>
A quotation from Swami Vivekananda, a Vedantist, offers a good example of the worry about free will in the Hindu tradition. Template:Bquote However, the preceding quote has often been misinterpreted as Vivekananda implying that everything is predetermined. What Vivekananda actually meant by lack of free will was that the will was not "free" because it was heavily influenced by the law of cause and effect – "The will is not free, it is a phenomenon bound by cause and effect, but there is something behind the will which is free."<ref name = "viveka"/> However, Vivekananda never said that it was absolutely determined and placed emphasis on the power of conscious choice to alter one's past Karma: "It is the coward and the fool who says this is his fate. But it is the strong man who stands up and says I will make my own fate."<ref name = "viveka"/>
Mimamsa, Vedanta, and the more theistic versions of Hinduism such as Shaivism and Vaishnavism, have often emphasized the importance of free will. The doctrine of Karma in Hinduism requires both that we pay for our actions in the past, and that our actions in the present be free enough to allow us to deserve the future reward or punishment that we will receive for our present actions.
In Buddhist philosophy
Buddhism accepts both freedom and determinism (or something similar to it), but rejects the idea of an agent, and thus the idea that freedom is a free will belonging to an agent.<ref name="Gier">Gier, Nicholas and Kjellberg, Paul. "Buddhism and the Freedom of the Will: Pali and Mahayanist Responses" in Freedom and Determinism. Campbell, Joseph Keim; O'Rourke, Michael; and Shier, David. 2004. MIT Press </ref> According to The Buddha, "There is free action, there is retribution, but I see no agent that passes out from one set of momentary elements into another one, except the [connection] of those elements."<ref name="Gier" /> Buddhists believe in neither absolute free will, nor determinism. It preaches a middle doctrine, named pratitya-samutpada in Sanskrit, which is often translated as "inter-dependent arising". It is part of the theory of karma in Buddhism. The concept of karma in Buddhism is different from the notion of karma in Hinduism. In Buddhism, the idea of karma is much less deterministic. The Buddhist notion of karma is primarily focussed on the cause and effect of moral actions in this life, while in Hinduism the concept of karma is more often connected with determining one's destiny in future lives.
In Buddhism it is taught that the idea of absolute freedom of choice (i.e. that any human being could be completely free to make any choice) is foolish, because it denies the reality of one's physical needs and circumstances. Equally incorrect is the idea that we have no choice in life or that our lives are pre-determined. To deny freedom would be to undermine the efforts of Buddhists to make moral progress (through our capacity to freely choose compassionate action). Pubbekatahetuvada, the belief that all happiness and suffering arise from previous actions, is considered a wrong view according to Buddhist doctrines. Because Buddhists also reject agenthood, the traditional compatibilist strategies are closed to them as well. Instead, the Buddhist philosophical strategy is to examine the metaphysics of causality. Ancient India had many heated arguments about the nature of causality with Jains, Nyayists, Samkhyists, Cārvākans, and Buddhists all taking slightly different lines. In many ways, the Buddhist position is closer to a theory of "conditionality" than a theory of "causality", especially as it is expounded by Nagarjuna in the Mūlamadhyamakakārikā.<ref name="Gier" />
In other theology
The theological doctrine of divine foreknowledge is often alleged to be in conflict with free will, particularly in Reformed circles. For if God knows exactly what will happen, right down to every choice one makes, the status of choices as free is called into question. If God had timelessly true knowledge about one's choices, this would seem to constrain one's freedom.<ref>Alston, William P. 1985. "Divine Foreknowledge and Alternative Conceptions of Human Freedom." International Journal for Philosophy of Religion 18:1, 19–32.</ref> This problem is related to the Aristotelian problem of the sea battle: tomorrow there will or will not be a sea battle. If there will be one, then it seems that it was true yesterday that there would be one. Then it would be necessary that the sea battle will occur. If there won't be one, then by similar reasoning, it is necessary that it won't occur.<ref>Aristotle. "De Interpretatione" in The Complete Works of Aristotle, vol. I, ed. Jonathan Barnes. Princeton University Press, Princeton, New Jersey, 1984.</ref> This means that the future, whatever it is, is completely fixed by past truths—true propositions about the future.
However, some philosophers follow William of Ockham in holding that necessity and possibility are defined with respect to a given point in time and a given matrix of empirical circumstances, and so something that is merely possible from the perspective of one observer may be necessary from the perspective of an omniscient.<ref name="ockham"> Ockham, William. Predestination, God's Knowledge, and Future Contingents, early 14th century, trans. Marilyn McCord Adams and Norman Kretzmann 1982, Hackett, esp p. 46–7</ref> Some philosophers follow Philo of Alexandria in holding that free will is a feature of a human's soul, and thus that non-human animals lack free will.<ref>H. A. Wolfson, Philo, 1947 Harvard University Press; Religious Philosophy, 1961 Harvard University Press; and "St. Augustine and the Pelagian Controversy" in Religious Philosophy </ref>
Jewish philosophy stresses that free will is a product of the intrinsic human soul, using the word neshama (from the Hebrew root n.sh.m. or .נ.ש.מ meaning "breath"), but the ability to make a free choice is through Yechida (from Hebrew word "yachid", יחיד, singular), the part of the soul which is united with God, the only being that is not hindered by or dependent on cause and effect (thus, freedom of will does not belong to the realm of the physical reality, and inability of natural philosophy to account for it is expected). In Islam the theological issue is not usually how to reconcile free will with God's foreknowledge, but with God's jabr, or divine commanding power. al-Ash'ari developed an "acquisition" or "dual-agency" form of compatibilism, in which human free will and divine jabr were both asserted, and which became a cornerstone of the dominant Ash'ari position.<ref>Watt, Montgomery. Free-Will and Predestination in Early Islam. Luzac & Co.: London 1948; Wolfson, Harry. The Philosophy of Kalam, Harvard University Press 1976 and Template:Dead link</ref> In Shia Islam, Ash'aris understanding of a higher balance toward predestination is challenged by most theologists<ref>Man and His Destiny</ref> . Free will, according to Shia Islamic doctrine is the main factor for man's accountability in his/her actions throughout life. All actions taken by man's free will are said to be counted on the Day of Judgement because they are his/her own and not God's.
The philosopher Søren Kierkegaard claimed that divine omnipotence cannot be separated from divine goodness.<ref>Jackson, Timothy P. (1998) "Arminian edification: Kierkegaard on grace and free will" in Cambridge Companion to Kierkegaard, Cambridge University Press, Cambridge, 1998.</ref> As a truly omnipotent and good being, God could create beings with true freedom over God. Furthermore, God would voluntarily do so because "the greatest good ... which can be done for a being, greater than anything else that one can do for it, is to be truly free."<ref>Kierkegaard, Søren. (1848) Journals and Papers, vol. III. Reprinted in Indiana University Press, Bloomington, 1967–78.</ref> Alvin Plantinga's "free will defense" is a contemporary expansion of this theme, adding how God, free will, and evil are consistent. Mackie, J.L. (1955) "Evil and Omnipotence," Mind, new series, vol. 64, pp. 200–212.
All volition is relative. In the originating sense, only the Father-I AM possesses finality of volition; in the absolute sense, only the Father, the Son, and the Spirit exhibit the prerogatives of volition unconditioned by time and unlimited by space. Mortal man is endowed with free will, the power of choice, and though such choosing is not absolute, nevertheless, it is relatively final on the finite level and concerning the destiny of the choosing personality.
Volition on any level short of the absolute encounters limitations which are constitutive in the very personality exercising the power of choice. Man cannot choose beyond the range of that which is choosable. He cannot, for instance, choose to be other than a human being except that he can elect to become more than a man; he can choose to embark upon the voyage of universe ascension, but this is because the human choice and the divine will happen to be coincident upon this point. And what a son desires and the Father wills will certainly come to pass.
In the mortal life, paths of differential conduct are continually opening and closing, and during the times when choice is possible the human personality is constantly deciding between these many courses of action. Temporal volition is linked to time, and it must await the passing of time to find opportunity for expression. Spiritual volition has begun to taste liberation from the fetters of time, having achieved partial escape from time sequence, and that is because spiritual volition is self-identifying with the will of God.
Volition, the act of choosing, must function within the universe frame which has actualized in response to higher and prior choosing. The entire range of human will is strictly finite-limited except in one particular: When man chooses to find God and to be like him, such a choice is superfinite; only eternity can disclose whether this choice is also superabsonite.
- McKenna, Michael, "Compatibilism", The Stanford Encyclopedia of Philosophy (Summer 2004 Edition), Edward N. Zalta (ed.),((online))
- Ginet, C. 1983. "In Defense of Incompatibilism" in Philosophical Studies 44, pp. 391–400
- Koons, J.R. "Is Hard Determinism a Form of Compatibilism?" in The Philosophical Forum. 33:1
- Strawson, G. (1998, 2004). "Free will". In E. Craig (Ed.), Routledge Encyclopedia of Philosophy. London: Routledge. Retrieved August 17, 2006, ((online))
- Vihvelin, Kadri, "Arguments for Incompatibilism", The Stanford Encyclopedia of Philosophy (Winter 2003 Edition), Edward N. Zalta (ed.),((online))
- Suppes, P., 1993, “The Transcendental Character of Determinism,” Midwest Studies in Philosophy, 18: 242–257.
- Fischer, John Martin (1989) God, Foreknowledge and Freedom. Stanford, CA: Stanford University Press. ISBN 1-55786-857-3
- Watt, Montgomery (1948) Free-Will and Predestination in Early Islam. London:Luzac & Co.
- Hobbes, T. (1651) Leviathan (1968 edition). London:Penguin Books
- Hume, D. (1740). A Treatise of Human Nature (1967 edition). Oxford University Press, Oxford. ISBN 0-87220-230-5
- See Bricklin, Jonathan, "A Variety of Religious Experience: William James and the Non-Reality of Free Will", in Libet (1999), The Volitional Brain: Toward a Neuroscience of Free Will (Thorverton UK: Imprint Academic).
- James, W. (1907) Pragmatism (1979 edition). Cambridge, MA: Harvard University Press
- Frankfurt, H. (1971) Freedom of the Will and the Concept of the Person in "Journal of Philosophy"
- Dennett, D., (1984) Elbow Room: The Varieties of Free Will Worth Wanting. Bradford Books. ISBN 0-262-54042-8
- Watson, D. 1982. Free Will. New York: Oxford University Press.
- Fischer, John Martin, and Mark Ravizza. 1998. Responsibility and Control: An Essay on Moral Responsibility. Cambridge: Cambridge University Press.
- Dennett, D. (2003) Freedom Evolves. Viking Books. ISBN 0-670-03186-0
- Kane, R. The Oxford Handbook to Free Will. Oxford University Press. ISBN 0-19-513336-6.
- van Invagen, P. (1983) An Essay on Free Will. Oxford:Clarendon Press. ISBN 0-19-824924-1
- Pereboom, D. (2003) Living without Free Will. Cambridge University Press.
- Fischer, J.M. (1983) "Incompatibilism" in Philosophical Studies. 43:121-37
- Kane, R. (1996) The Significance of Free Will, Oxford:Oxford University Press. ISBN 0-19-512656-4
- Campbell, C.A. (1957) On Selfhood and Godhood, London: George Allen and Unwin. ISBN 0-415-29624-2
- Sartre, J.P. (1943) Being and Nothingness, reprint 1993. New York:Washington Square Press. Sartre also provides a psychological version of the argument by claiming that if man's actions are not his own, he would be in bad faith.
- Fischer, R.M. (1994) The Metaphysics of Free Will, Oxford:Blackwell
- Bok, H. (1998) Freedom and Responsibility, Princeton:Princeton University Press. ISBN 0-691-01566-X
- Ginet, C. (1966) "Might We Have No Choice?" In Lehrer, 1966: 87–104.
- Van Inwagen, P. and Zimmerman, D. (1998) Metaphysics: The Big Questions. Oxford:Blackwell
- Inwagen, P. (n.d.) "How to think about free will", p. 15.
- Lewis, D. "Are We Free to Break the Laws?" in Theoria, 47:113–21
- "Naturalistic, Libertarian Free Will". Peter Ells.[dead links]
- Locke, J. (1689). An Essay Concerning Human Understanding (1998, ed). Book II, Chap. XXI, Sec. 17. Penguin Classics, Toronto.
- Hume, D. (1765)An Enquiry Concerning Human Understanding, Indianaplolis: Hacket Publishing Co. Second edition. 1993. ISBN 0-87220-230-5
- Schopenhauer, Arthur, The Wisdom of Life, p 147
- Schopenhauer, Arthur, On the Freedom of the Will, Oxford: Basil Blackwell ISBN 0-631-14552-4
- Rudolf Steiner. "Arthur Schopenhauers sämtliche Werke in zwölf Bänden. Mit Einleitung von Dr. Rudolf Steiner, Stuttgart: Verlag der J.G. Cotta'schen Buchhandlung Nachfolger, o.J. [1894-96]".
- Steiner, R. (1964). Rudolf Steiner Press, London, 1964, 1970, 1972, 1979, 230 pp., translated from the 12th German edition of 1962 by Michael Wilson. ((online))
- Honderich, T. "Determinism as True, Compatibilism and Incompatibilism as Both False and the Real Problem" in The Free Will Handbook , edited by Robert Kane of the University of Texas, published by Oxford University Press in 2001.
- Benditt, Theodore (1998) Philosophy Then and Now with eds. Arnold and Graham. Oxford: Blackwell Publishing, 1998. ISBN 1-55786-742-9
- Darrow, Clarence, 1924, “The Plea of Clarence Darrow, in Defense of Richard Loeb and Nathan Leopold, Jr., On Trial for Murder” page reference is to the reprint in Philosophical Explorations: Freedom, God, and Goodness, S. Cahn (ed.), New York: Prometheus Books, 1989.
- Sartre, J.P. (1943) Being and Nothingness, reprint 1993. New York:Washington Square Press.
- O'Connor, Timothy ed. Agents, Causes, & Event: Essays on Indeterminism and Free Will, 1995 Oxford University Press.
- St. Paul, "Epistle to the Romans", 9:21, King James Bible Tennessee:The Gideons International
- Vuoso, G. (1987) "Background Responsibility and Excuse," Yale Law Journal, 96, pp. 1680–81
- Cummins, R. "Culpability" and Mental Disorder", p. 244
- Goldstein, A. M., Morse, S. J. & Shapiro, D. L. 2003 "Evaluation of criminal responsibility". In Forensic psychology. vol. 11 (ed. A. M. Goldstein), pp. 381–406. New York: Wiley.
- Greene, J. Cohen, J. (2004). "For the law, neuroscience changes nothing and everything". Philosophical Transactions of the Royal Society of London B, 359, 1775–1785.
- Brower M.C. and Price B.H. (2001). "Neuropsychiatry of frontal lobe dysfunction in violent and criminal behaviour: a critical review". Journal of Neurology, Neurosurgery and Psychiatry, 71: 720–726.
- Steinberg, L., Scott, E. S. (2003). "Less guilty by reason of adolescence: developmental immaturity, diminished responsibility, and the juvenile death penalty". American Psychologist 58, 1009–1018.
- Teicher, M. H., Anderson, S. L., Polcari, A., Anderson, C. M., Navalta, C. P., and Kim, D. M. (2003). "The neurobiological consequences of early stress and childhood maltreatment". Neuroscience and Behavioral Reviews, 27: 33–44.
- for example in the thought of Democritus or the Cārvākans
- Boniolo, G. and Vidali, P. (1999) Filosofia della Scienza, Milan: Mondadori. ISBN 88-424-9359-7
- Davies, P. Chaos Frees the Universe
- Honderich, E. Determinism as True, Compatibilism and Incompatibilism as Both False, and the Real Problem
- Ghirardi, G. (1997) Un' Occhiata alle Carte di Dio. Milan:Il Saggiatore. ISBN 88-428-0947-0
- Reason Online. Freedom Evolves
- Kane, Robert. 1996b. The Significance of Free Will. New York: Oxford University Press. ISBN 0-19-512656-4
- Pinel, P.J. (1990) Biopsychology. Prentice Hall Inc. ISBN 88-15-07174-1
- DeFries, J. C., McGuffin, P., McClearn, G. E., Plomin, R. (2000) Behavioral Genetics 4th ED. W H Freeman & Co.
- Morris, D. (1967) The Naked Ape. New York:McGraw-Hill. ISBN 0-385-33430-3
- Dawkins, R. (1976) The Selfish Gene. Oxford:Oxford University Press. ISBN 88-04-39318-1
- Pinker, S.(2002) The Blank Slate: The Modern Denial of Human Nature. London:Penguin. p.179 ISBN 0-14-200334-4
- Lewontin, R. (2000)It Ain't Necessarily So:The Dream of the Human Genome and other Illusions. New York:NYREV Inc. ISBN 88-420-6418-1
- Libet, B., Gleason, C.A., Wright, E.W., Pearl, D.K. (1983). Time of conscious intention to act in relation to onset of cerebral activity (readiness-potential). The unconscious initiation of a freely voluntary act. Brain. 106 (3):623–642. PMID 6640273
- Libet, B. (1985) Unconscious cerebral initiative and the role of conscious will in voluntary action. Behavioral and Brain Sciences, 8: 529–566.
- Dennett, D. (1991) Consciousness Explained. The Penguin Press. ISBN 0-7139-9037-6 (UK Hardcover edition, 1992) ISBN 0-316-18066-1 (paperback)
- Dennett, Daniel C and Marcel, Kinsbourne (1992)Time and the Observer. Behavioral and Brain Sciences 15(2), 183–247.
- Haggard, P. and Eimer, M. (1999). On the relation between brain potentials and the awareness of voluntary movements. Experimental Brain Research 126, 128–133. PMID 10333013
- Trevena, J.A. and Miller, J. (2002). Cortical movement preparation before and after a conscious decision to move. Consciousness and Cognition 11, 162–190. PMID 12191935
- Haggard, P. (2005). Conscious intention and motor cognition. Trends in Cognitive Sciences 9, 6 : 290–295. PMID 15925808
- Ammon, K. and Gandevia, S.C. (1990) Transcranial magnetic stimulation can influence the selection of motor programmes. Journal of Neurology, Neurosurgery and Psychiatry 53: 705–707. PMID 2213050
- Brasil-Neto, J.P., Pascual-Leone, A., Valls-Solé, J., Cohen, L.G. and Hallett, M. (1992) Focal transcranial magnetic stimulation and response bias in a forced-choice task. Journal of Neurology, Neurosurgery and Psychiatry 55: 964–966. PMID 1431962
- Libet, (2003). "Can Conscious Experience affect brain Activity?", Journal of Consciousness Studies 10, nr. 12, pp 24–28.
- Velmans, M. (2003) "Preconscious free will", Journal of Consciousness Studies 10, nr. 12, pp 42–61.
- Tourette Syndrome Association. Definitions and Classification of Tic Disorders. Accessed 19 Aug 2006.
- Zinner S.H. (2000) Tourette disorder. Pediatric Review, 21(11):372. PMID 11077021
- Doody RS, Jankovic J. (1992). The alien hand and related signs. Journal of Neurology, Neurosurgery and Psychiatry, 55:806–810. PMID 1402972
- Scepkowski, L.A., & Cronin-Golomb, A. (2003). The alien hand: cases, categorizations, and anatomical correlates. Behavioral and Cognitive Neuroscience Reviews, 2(4):261–277. PMID 15006289
- Bundick, T., Spinella, M. (2000). Subjective experience, involuntary movement, and posterior alien hand syndrome. Journal of Neurology, Neurosurgery and Psychiatry, 68:83–85 PMID 10601408
- Schneider, K. (1959). Clinical Psychopathology. New York: Grune and Stratton.
- Frith CD, Blakemore S, Wolpert DM. (2000). Explaining the symptoms of schizophrenia: abnormalities in the awareness of action. Brain Brain Research Reviews. 2000 Mar;31(2-3):357-63. PMID 10719163
- Kenrick, D. T., Li, N. P., & Butner, J. (2003). "Dynamical evolutionary psychology: Individual decision rules and emergent social norms." Psychological Review, 2003 Jan;110(1):3–28. PMID 12529056
- Epstein J.M. and Axtell R. (1996) Growing Artificial Societies - Social Science from the Bottom. Cambridge MA, MIT Press.
- Wolfram, Stephen, A New Kind of Science. Wolfram Media, Inc., May 14, 2002. ISBN 1-57955-008-8
- Wegner, D.M. (2002). The illusion of conscious will. Cambridge, MA: MIT Press.
- Wegner, D.M. & Wheatley, T. (1999). Apparent mental causation: sources of the experience of will. American Psychologist, 54, 480-491.
- Koller, J. (2007) Asian Philosophies. 5th ed. Prentice Hall. ISBN 0-13-092385-0
- Swami Vivekananda (1907) "Freedom" from The Complete Works of Swami Vivekananda. vol. 1.
- Gier, Nicholas and Kjellberg, Paul. "Buddhism and the Freedom of the Will: Pali and Mahayanist Responses" in Freedom and Determinism. Campbell, Joseph Keim; O'Rourke, Michael; and Shier, David. 2004. MIT Press
- Alston, William P. 1985. "Divine Foreknowledge and Alternative Conceptions of Human Freedom." International Journal for Philosophy of Religion 18:1, 19–32.
- Aristotle. "De Interpretatione" in The Complete Works of Aristotle, vol. I, ed. Jonathan Barnes. Princeton University Press, Princeton, New Jersey, 1984.
- Ockham, William. Predestination, God's Knowledge, and Future Contingents, early 14th century, trans. Marilyn McCord Adams and Norman Kretzmann 1982, Hackett, esp p. 46–7
- H. A. Wolfson, Philo, 1947 Harvard University Press; Religious Philosophy, 1961 Harvard University Press; and "St. Augustine and the Pelagian Controversy" in Religious Philosophy
- Watt, Montgomery. Free-Will and Predestination in Early Islam. Luzac & Co.: London 1948; Wolfson, Harry. The Philosophy of Kalam, Harvard University Press 1976 and [dead links]
- Man and His Destiny
- Jackson, Timothy P. (1998) "Arminian edification: Kierkegaard on grace and free will" in Cambridge Companion to Kierkegaard, Cambridge University Press, Cambridge, 1998.
- Kierkegaard, Søren. (1848) Journals and Papers, vol. III. Reprinted in Indiana University Press, Bloomington, 1967–78.
- Mackie, J.L. (1955) "Evil and Omnipotence," Mind, new series, vol. 64, pp. 200–212.
- Life is unpreditable get used to it article in New Scientist
- Bischof, Michael H. (2004). Kann ein Konzept der Willensfreiheit auf das Prinzip der alternativen Möglichkeiten verzichten? Harry G. Frankfurts Kritik am Prinzip der alternativen Möglichkeiten (PAP). In: Zeitschrift für philosophische Forschung (ZphF), Heft 4.
- Epstein J.M. (1999). Agent Based Models and Generative Social Science. Complexity, IV (5).
- Gazzaniga, M. & Steven, M.S. (2004) Free Will in the 21st Century: A Discussion of Neuroscience and Law, in Garland, B. (ed.) Neuroscience and the Law: Brain, Mind and the Scales of Justice, New York: Dana Press, ISBN 1932594043, pp51–70.
- Goodenough, O.R. (2004) Responsibility and punishment, Philosophical Transactions of the Royal Society: Biological Sciences (Special Issue: Law and the Brain), 359, 1805–1809.
- Hofstadter, Douglas. (2007) I Am A Strange Loop. Basic Books. ISBN 978-0465030781
- Kane, Robert (1998). The Significance of Free Will. New York: Oxford University Press ISBN 0-19-512656-4
- Lawhead, William F. (2005). The Philosophical Journey: An Interactive Approach. McGraw-Hill Humanities/Social Sciences/Languages ISBN 0-07-296355-7.
- Libet, Benjamin; Anthony Freeman; and Keith Sutherland, eds. (1999). The Volitional Brain: Towards a Neuroscience of Free Will. Exeter, UK: Imprint Academic. Collected essays by scientists and philosophers.
- Morris, Tom Philosophy for Dummies. IDG Books ISBN 0-7645-5153-1.
- Muhm, Myriam (2004). Abolito il libero arbitrio - Colloquio con Wolf Singer. L'Espresso 19.08.2004 http://www.larchivio.org/xoom/myriam-singer.htm
- Nowak A., Vallacher R.R., Tesser A., Borkowski W. (2000). Society of Self: The emergence of collective properties in self-structure. Psychological Review. 107
- Schopenhauer, Arthur (1839). On the Freedom of the Will., Oxford: Basil Blackwell ISBN 0-631-14552-4.
- Van Inwagen, Peter (1986). An Essay on Free Will. New York: Oxford University Press ISBN 0-19-824924-1.
- Velmans, Max (2003) How Could Conscious Experiences Affect Brains? Exeter: Imprint Academic ISBN 0907845-39-8.
- Wegner, D. (2002). The Illusion of Conscious Will. Cambridge: Bradford Books
- Williams, Clifford (1980). Free Will and Determinism: A Dialogue. Indianapolis: Hackett Publishing Co.
- Stanford Encyclopedia of Philosophy entries:
- "Free Will" by Galen Strawson in Routledge Encyclopedia of Philosophy
- Free will, evolution and chaos theory
- The Nature of Free Will by Peter Voss
- Article at Roman Catholic Encyclopedia
- Article at Determinism and Freedom Philosophy Website
- An Introduction to Free Will and Determinism by Paul Newall, aimed at beginners.
- "How to think about the problem of free will" by Peter van Inwagen
- The Garden of Forking Paths--a blog on free will and action theory written by top experts