separate ontological class to physical properties: that mental states (such as qualia) are not ontologically reducible to physical states. Although one Free will is generally understood as the capacity or ability of people to (a) choose between different possible courses of action, (b) exercise control over their actions in a way that is necessary for moral responsibility, or (c) be the ultimate source or originator of their actions. There are different theories as to its nature, and these aspects are often emphasized differently depending on phi Determinism (D) is true, D does not imply we lack free will (F), but in fact we do lack F. D is true, D does not imply we lack F, but in fact we don't know if we have F. D is true, and we do have F. D is true, we have F, and F implies D. D is unproven, but we have F. D isn't true, we do have F, and would have F even if D were true. D isn't true, we don't have F, but F is compatible with D. Derk Pereboom, Living without Free Will, p. xvi. Pereboom calls positions 3 and 4 soft determinism, position 1 a form of hard determinism, position 6 a form of classical libertarianism, and any position that includes having F as compatibilism. John Locke 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 people can 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". 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… The… In 1739, David Hume in his A Treatise of Human Nature approached free will via the notion of causality. It was his position that causality was a 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 to be responsible in some situation S, one must have been responsible for the way one was at S−1. Physicalism is a philosophical theory holding that everything that exists is no more extensive than its physical properties; that is, that there are no non-physical substances (for example physically independent minds). Physicalism can be reductive or non-reductive. Reductive physicalism is grounded in the idea that everything in the world can actually be reduced analytically to its fundamental physical, or material, basis. Alternatively, non-reductive physicalism asserts that mental properties form a separate ontological class to physical properties: that mental states (such as qualia) are not ontologically reducible to physical states. It was his position that causality was a mental construct used to explain the repeated association of events, and that one must examine more closely the relation between things regularly succeeding one another (descriptions of regularity in nature) and things that result in other things (things that cause or necessitate other things). According to Hume, 'causation' is on weak grounds: "Once we realise that 'A must bring about B' is tantamount merely to 'Due to their constant conjunction, we are psychologically certain that B will follow A,' then we are left with a very weak notion of necessity." This empiricist view was often denied by trying to prove the so-called apriority of causal law (i.e. 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). === Genetics === 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. While it is established that randomness is not the only factor in the perception of the free will, it has been shown that randomness can be mistaken as free will due to its indeterminacy. This misconception applies both when considering oneself and others. Another contribution is choice. It has been demonstrated that people's belief in free will increases if presented with a simple level of choice. The specificity of the amount of choice is important, as too little or too great a degree of choice may negatively influence belief. It is also likely that the associative relationship between level of choice and perception of free will is influentially bidirectional.