1. An example of a more precise definition is that offered by Van Inwagen as the conjunction of these two propositions:

1. (a)

   (a) For every instant of time, there is a proposition that expresses the state of the world at that instant.

2. (b)

   (b) If A and B are any propositions that express the state of the world at some instants, then the conjunction of A with the laws of physics entails B.

See P Van Inwagen, “The Incompatibility of Free Will and Determinism” (1975) 27 Philosophical Studies 185 at 186. Determinism can also be framed in epistemological terms in reference to predictability. Simon-Pierre Laplace posited that an entity that knows the exact conditions of the universe at any particular moment and all the natural laws that govern the universe would be able to predict the future, down to the smallest detail (Pierre Simon Laplace, A Philosophical Essay on Probabilities, 6th ed, translated by FW Truscott & FL Emory (New York: Dover Publications, 1951) at 4). The nature of the laws of nature and of causality, of course, are long-standing and expansive philosophical problems—problems that will not detain us here.

2. This is not a wholly settled matter. There are deterministic interpretations of quantum mechanics. See, for example, Hrvoje Nikolic, “Bohemian Particle Trajectories in Relativistic Bosonic Quantum Field Theory” (2004) 17 Foundations of Physics Letters 363.

3. See, for example, Pereboom, Derk, Living without Free Will (Cambridge: Cambridge University Press, 2001).CrossRefGoogle Scholar

4. See, for example, John M Fischer, “Incompatibilism” (1980) 43 Philosophical Studies 127. Whether alien systems can possess free will or various other properties of mind is a matter of active debate. One of the criticisms of type-physicalist theories of mind—theories that ascribe a one-to-one correspondence between mental states and physical states—is that they necessitate an essentialist equating of our mental states with our specific physiological make-up. The result is that creatures of similar structural complexity to ourselves, but who are silicon-based rather than carbon-based, for example, could not possess intentionality, consciousness, etc. Other physicalist monist theories of mind—token identity or functionalist theories that see mental states as residing in the organizational structure (or “software”) of the mind—recognize the potential for non-human creatures or machines to have mental states very similar to our own. See, for example, Young, Gary, Philosophical Psychopathology: Philosophy without Thought Experiments (Hampshire, UK: Palgrave Macmillan, 2013).CrossRefGoogle Scholar

5. See, for example, Kane, Robert, The Significance of Free Will (Oxford: Oxford University Press, 1998).Google Scholar

6. While the reductionism that usually accompanies physicalist monism may throw the deterministic challenge in particularly stark relief, it is not necessary to determinism per se. If psychological or sociological laws have causal effect, then they could operate deterministically even if they are not fully reducible to physical laws.

Further, it is conceivable to have an idealist or dualist conception of determinism in which mental states as non-physical substances operate through causal sufficiency to produce particular subsequent mental states to the preclusion of other potential ones. This would offer a solution to some of the problems for physicalist theories of mind—the problem of qualia and the distinctly subjective, phenomenological quality of what it is like to have a specific experience, for example, something that seems hard to reduce to physical states. Traditional problems for dualism and idealism, such as ascertaining the nature of this non-physical substance, would remain—as would the problem of free will (the question now being how one could have acted contrary to dictates of prior mental—rather than physical—states).

7. Classic early exponents of compatibilism in modern western philosophy include Thomas Hobbes and David Hume.

8. In this regard, libertarianism is actually a form of incompatibilism, one that reconciles the incompatibility between free will and determinism by denying the latter rather than the former.

9. See, for example, Robert Kane, “Free Will: New Directions for an Ancient Problem” in Robert Kane, ed, Free Will (Malden: Blackwell, 2001).

10. René Descartes was a classic early exponent of this view. See René Descartes, “Passions of the Soul”, The Philosophical Works of Descartes, vol 1, translated by ES Haldane & GRT Ross (London: Cambridge University Press, 1931).

11. See, for example, Nozick, Robert, Philosophical Explanations (Cambridge: Harvard University Press, 1981) at 298.Google Scholar

12. See, for example, Sabine Hossenfelder, “The Free Will Function” (2012) ArXiv12020720 Phys.

13. The fourth logical position, that human beings are indeterministic but do not have free will, is not widely advanced. But if determinism is accepted and the libertarian cannot meet the challenge of reconciling it with free will, then the essential randomness of the universe could be seen as foreclosing the possibility for true freedom.

14. Eliminative materialism sees brain states as completely explaining mental states, with the result that our common sense understanding of the latter is wholly mistaken. Other physicalist theories (token identity theories or functionalist theories) see brain states as sufficient but not necessary instantiations of mental states, such that the same mental states could arise from other types of physical forms. Emergentism is a non-reductive physicalism holding that structures or systems of sufficient complexity may exhibit qualities that cannot be reduced to lower level components. Just as water has properties distinct from its component atoms of hydrogen and oxygen, the brain manifests supervening properties (in the form of mental states) that cannot be wholly located in the sum of neurons, synapses or other component parts.

15. Certainly, many commentators seem keen to map particular aspects of human behaviour to particular anatomical features of the brain in a one-to-one manner. (See, for example, Knabb et al, “Neuroscience, Moral Reasoning, and the Law” (2009) 27 Behavioral Sciences and the Law 219.) This tendency risks eliminating explanations that may not actually be fully reducible to more “fundamental” theoretical levels. It may be, for example, that the functionalism present in biological explanations is particularly relevant to explaining the operation of the brain and neurological system, yet it is eliminated in an overly isolationist anatomical approach.

16. Stephen J Morse, “Avoiding Irrational NeuroLaw Exuberance: A Plea for Neuromodesty” (2011) 3 Law, Innovation and Technology 209 at 215. Michael S Moore, “Responsible Choices, Desert-Based Legal Institutions, and the Challenges of Contemporary Neuroscience” (2012) 29 Social Philosophy and Policy 233.

17. Morse’s own position is compatibilism, which he contends is consistent with the legal principles relevant to criminal responsibility.

18. For example, see Michael S Moore, “Causation and Excuses” (1985) 73 Cal L Rev 1091 at 1128-37.

19. See Michael S Moore, “Stephen Morse on the Fundamental Psycho-Legal Error” (2016) 10 Criminal Law and Philosophy 45.

20. Ibid.

21. Moore, supra note 18. The primary function of the law is as a guide to action. Hence, the law operates on the folk psychological realm of reasons and intentions. Whereas the mechanistic approach of neuroscience, at least at its present level of development, cannot fulfil this normative role, it may, nonetheless, help in the application of legal doctrine, e.g., in determining whether a genuine excuse existed or potentially inform rehabilitative measures See also, Stephen J Morse, “Determinism and the Death of Folk Psychology: Two Challenges to Responsibility from Neuroscience” (2008) 9 Minn JL Sci & Tech 1. Morse is critical of the legal system for being too often overly deferential to scientific expertise. See, for example, Stephen J Morse, “The New Syndrome Excuse Syndrome” (1995) 14 Criminal Justice Ethics 3. Here he agrees with Robin Feldman, who sees strategies of both “internalization” and “externalization” at work. In the former, the law adopts scientific criteria as legal criteria, while in the latter, legal decision-making is essentially outsourced to experts from other fields. See Feldman, Robin, The Role of Science in Law (New York: Oxford University Press, 2009).CrossRefGoogle Scholar

22. Both Moore and Morse expound their case through extensive and often subtle argumentation, a full engagement with which is beyond the scope and aims of this paper. See, for example, Stephen J Morse, “Avoiding Irrational NeuroLaw Exuberance: A Plea for Neuromodesty” (2011) 3 Law, Innovation and Technology 209 at 215; “Determinism and the Death of Folk Psychology: Two Challenges to Responsibility from Neuroscience” (2008) 9 Minn. JL Sci & Tech 1; ‘‘The Non-Problem of Free Will in Forensic Psychiatry and Psychology’’ (2007) 25 Behavioral Sciences and the Law 203; “Uncontrollable Urges and Irrational People Essay” (2002) 88 Va L Rev 1025; “The New Syndrome Excuse Syndrome” (1995) 14 Criminal Justice Ethics 3; “Treating Crazy People Less Specially” (1988) 90 W Va L Rev 353; “Failed Explanations and Criminal Responsibility: Experts and the Unconscious” (1982) 68 Va L Rev 971; Michael S Moore, “Stephen Morse on the Fundamental Psycho-Legal Error” (2016) 10 Criminal Law and Philosophy 45; “Responsible Choices, Desert-Based Legal Institutions, and the Challenges of Contemporary Neuroscience” (2012) 29 Social Philosophy and Policy 233; “Causation and the Excuses” (1985) 73 Cal L Rev at 1091; “Responsibility and the Unconscious” (1980) 53 S Cal L Rev 1563; “Failed Explanations and Criminal Responsibility: Experts and the Unconscious” (1982) 68 Va L Rev 971.

23. A classic statement of capacity as the basis for responsibility (or the lack thereof) is found in Hart:

24. Stone (1999) 154 CCC (3d) 353. The defence of mental disorder is codified in section 16 of the Criminal Code, RSC 1985, c C-46 which states, in part:

25. The somewhat complicated state of Canadian law at present is that extreme self-induced intoxication that induces a state “akin to automatism or insanity” could be a complete defence to charges that do not involve personal violence or the threat thereof. For these offences, self-induced automatism at most amounts to a partial defence. (See Daviault [1994] 3 SCR 63 and the Parliamentary response of section 33.1 of the Criminal Code.)

26. In limiting automatism as a defence in the case of self-induced intoxication, the courts are looking to a broader situational culpability that invokes responsibility for the conditions leading to the inducement of the automatistic state. Free will retains its relevance in the accused’s choice to willingly put himself in a state in which criminal behaviour was a foreseeable possibility.

27. It should be noted that a lack of consciousness is not a necessary condition for involuntariness more generally. In the case of a reflex response, for example, the individual may be completely conscious and aware of what is happening, the key element being a lack of control.

28. Parks [1992] 2 SCR 871, 75 CCC (3d) 387.

29. This presupposition fulfils an inherently moral role. The Supreme Court of Canada, for example, has indicated that the distinction between subjective and objective mens rea reflects differing degrees of moral fault and that the application of either standard must reflect the proportionality between this moral fault and the gravity of the offence (in accord with the principle of fundamental justice). See Creighton [1993] 3 SCR 3, 83 CCC (3d) 356 (SCC).

30. Intoxication can be another such circumstance. Despite the complexity of the current state of Canadian law regarding the defence of intoxication, the courts seem primarily concerned with intoxication as impairing the capacity to make a reasonable choice, rather than the ability to choose at all.

Given the focus here on mental disorder, it is beyond the bounds of this paper to consider the full range of legal areas where issues of choice come to bear, but the defences of necessity and duress are worth a passing consideration. Defences of necessity or duress do not technically negate mens rea (but instead offer a justification or excuse for forming the mens rea in the first place). Nevertheless they point to a restriction of choice that is interesting to consider, in this case the result of some external force, constraint or set of circumstances that limits the reasonableness of obeying the law, requiring either a supererogatory act or, conversely, the overriding of basic human sentiment and moral imperative. In both situations, formal voluntariness is retained. The agent could have acted otherwise but an expectation that she do so is unreasonable (or unethical). The act is not unfree in the counterfactual sense of modal necessity. I could have chosen otherwise—merely at great personal risk. At an existential level, my freedom persists. At some point, however, the morally normative or instinctual pull becomes sufficiently powerful that it makes resistance genuinely impossible, perhaps even precluding its contemplation. The reality that under a libertarian or compatibilist framework there exists a tension between a presumption of freedom and a recognition that morally normative restraints on choice can bleed into areas where choice is seen as more formally constrained points to the utility of the Strawson’s pragmatically grounded participant/objective distinction described below.

31. See section 16, Criminal Code, also sections 672.1 and 672.34.

32. Peter Frederick Strawson, “Freedom and Resentment” in D Pereboom, ed, Free Will (Indianapolis: Hackett, 1997) 119.

33. Ibid at 129.

34. Ibid at 139.

35. Ibid at 123.

36. Other similar types of situation not mentioned by Strawson but where a lack ill-will mollifies resentment, would be where a degree of harm is justified by some greater good, pushing someone out of the way to save a child from an on-coming vehicle, etc.

37. Supra note 23 at 126.

38. Ibid at 140.

39. Ibid at 129.

40. See Michael McKenna & Paul Russell, eds, Free Will and Reactive Attitudes: Perspectives on P.F. Strawson’s “Freedom and Resentment” (Surrey, UK: Ashgate, 2008).

41. Ibid.

42. Ibid at 10-11. Also Derk Pereboom, “Alternate Possibilities and Causal Histories” (2000) 14 Philosophical Perspectives 119.

43. Indulging the penchant of philosophers for examples that involves wiring up people’s brains can help illustrate this difficulty. McKenna and Russell ask us to imagine a case where our basic dispositions were somehow “implanted” by means of an artificial technique (e.g., neurosurgery or genetic engineering). For a “normal” (i.e., rational) adult who is capable of manifesting good or ill will towards others, “worries about implantation will not and cannot dislodge or discredit our reactive attitudes. Contrary to this view, however, critics will argue that implantation evidently eliminates the agent’s moral responsibility and so there is something wrong with Strawson’s theory” (ibid at 13).

44. One shift that should be part of this program is away from Strawson’s assumption of the exclusivity of attitudes, meaning that we demonstrate at any one time and to any particular individual either participant or objective responses. It would seem that we can and do hold both simultaneously in a varying balance. We do not (normally) temporarily cease to view the child as human merely because we realize that he is not capable of fully-realized moral decisions.

45. Harry Frankfurt, “Freedom of the Will and the Concept of a Person” (1971) 68 Philosophy 5.

46. Michael Slote, “Understanding Free Will” (1980) 77 Journal of Philosophy 136.

47. Stephen J Morse, “Craziness and Criminal Responsibility” (1999) 17 Behavioral Sciences and the Law at 147.

48. And it should always be recognized that there likely are epistemological limits on the extent to which fundamental properties of persons can be ascertained via an object-oriented attitude—the degree to which can the self can contain itself as an object of its own knowledge. As well, the autopoetic quality of mind—the capacity for self-creation that emerges though dialectical engagement with self—does not have to be outside of physical law to unfold in non-algorithmic and not fully predictable ways.