Free will

The problem of free will has been identified in ancient Greek philosophical literature. The notion of compatibilist free will has been attributed to both Aristotle (4th century BCE) and Epictetus (1st century CE): "it was the fact that nothing hindered us from doing or choosing something that made us have control over them". According to Susanne Bobzien, the notion of incompatibilist free will is perhaps first identified in the works of Alexander of Aphrodisias (3rd century CE): "what makes us have control over things is the fact that we are causally undetermined in our decision and thus can freely decide between doing/choosing or not doing/choosing them".

The term "free will" (liberum arbitrium) was introduced by Christian philosophy (4th century CE). It has traditionally meant (until the Enlightenment proposed its own meanings) lack of necessity in human will, so that "the will is free" meant "the will does not have to be such as it is". This requirement was universally embraced by both incompatibilists and compatibilists.

The underlying questions are whether we possess the control over our actions we feel we have, and if so, what sort or amount of control do we exercise over our voluntary behavior. These ancient philosophical problems predate the early Greek stoics (for example, Chrysippus), and some modern philosophers still lament the lack of progress over all these centuries.

On one hand, humans have a strong sense of freedom, agency, and self-determination, which leads to a natural belief in free will and a sense of self. On the other hand, an intuitive feeling of free will could be mistaken.

It is difficult to reconcile the intuitive evidence that conscious decisions are causally effective with the view that the physical world can be explained entirely by physical law. The conflict between intuitively felt freedom and natural law arises when either causal closure or physical determinism (nomological determinism) is asserted. With causal closure, no physical event has a cause outside the physical domain, and with physical determinism, the future is determined entirely by preceding events (cause and effect).

The puzzle of reconciling 'free will' with a deterministic universe is known as the problem of free will or sometimes referred to as the dilemma of determinism. This dilemma leads to a moral dilemma as well: the question of how to assign responsibility for actions if they are caused entirely by past events.

Compatibilists maintain that mental reality is not of itself causally effective. Classical compatibilists have addressed the dilemma of free will by arguing that free will holds as long as humans are not externally constrained or coerced. Modern compatibilists make a distinction between freedom of will and freedom of action, that is, separating freedom of choice from the freedom to enact it. Given that humans all experience a sense of free will, some modern compatibilists think it is necessary to accommodate this intuition. Compatibilists often associate freedom of will with the ability to make rational decisions.

A different approach to the dilemma is that of incompatibilists, namely, that if the world is deterministic, then our feeling that we are free to choose an action is simply an illusion. Metaphysical libertarianism is the form of incompatibilism which posits that determinism is false and free will is possible (at least some people have free will). …

Buddhism accepts both freedom and determinism (or something similar to it), but despite its focus on human agency, it rejects the western concept of a total agent from external sources. 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." Buddhists believe in neither absolute free will, nor determinism. It preaches a middle doctrine, named pratītyasamutpāda in Sanskrit, often translated as "dependent origination", "dependent arising" or "conditioned genesis". It teaches that every volition is a conditioned action as a result of ignorance. In part, it states that free will is inherently conditioned and not "free" to begin with. It is also 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 focused 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 (that is that any human being could be completely free to make any choice) is unwise, because it denies the reality of one's physical needs and circumstances. Equally incorrect is the idea that humans have no choice in life or that their lives are pre-determined. To deny freedom would be to deny 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. …

Modern science is a mixture of deterministic and stochastic theories. Current physical theories cannot resolve the question of whether determinism is true of the world, being very far from a potential theory of everything, and open to many different interpretations.

Assuming that an indeterministic interpretation of quantum mechanics is correct, one may still object that such indeterminism is for all practical purposes confined to microscopic phenomena. A more significant question is whether the indeterminism of quantum mechanics allows for the traditional idea of free will (based on a perception of free will). If a person's action is, however, only a result of complete quantum randomness, mental processes as experienced have no influence on the probabilistic outcomes (such as volition). According to many interpretations, indeterminism enables free will to exist, while others assert the opposite (because the action was not controllable by the physical being who claims to possess the free will).

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. The view of many researchers is that many human behaviors can be explained in terms of humans' brains, genes, and evolutionary histories. 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 does not require that behavior be uncaused, as long as behavior responds to praise and blame. Moreover, it is not certain that environmental determination is any less threatening to free will than genetic determination.

It has become possible to study the living brain, and researchers can now watch the brain's decision-making process at work. …