Derk Pereboom offers a "hard incompatibilism" that makes both free will and moral responsibility incompatible with determinism. Although Pereboom claims to be agnostic about the truth of determinism, he argues that we should admit there is neither human freedom nor moral responsibility and that we should learn to live without free will. He is close to a group of thinkers who share a view that William James called "hard determinism," including Richard Double, Ted Honderich, Saul Smilansky, Galen Strawson, and the psychologist Daniel Wegner. Some of them call for the recognition that "free will is an illusion." But note that Pereboom's "hard incompatibilism" is not only the case if determinism is true. He argues that it is equally the case if indeterminism is true. Pereboom says that neither provides the control needed for moral responsibility. This is the standard argument against free will. As Pereboom states his view:
I argue for a position closely related to hard determinism. Yet the term "hard determinism" is not an adequate label for my view, since I do not claim that determinism is true. As I understand it, whether an indeterministic or a deterministic interpretation of quantum mechanics is true is currently an open question. I do contend, however, that not only is determinism incompatible with moral responsibility, but so is the sort of indeterminacy specified by the standard interpretation of quantum mechanics, if that is the only sort of indeterminacy there is.In his 1995 essay stating the case for "Hard Incompatibilism," Pereboom notes...
The demographic profile of the free will debate reveals a majority of soft determinists, who claim that we possess the freedom required for moral responsibility, that determinism is true, and that these views are compatible. Libertarians, incompatibilist champions of the freedom required for moral responsibility, constitute a minority. Not only is this the distribution in the contemporary philosophical population, but in Western philosophy has always been the pattern. Seldom has hard determinism — the incompatibilist endorsement of determinism and rejection of the freedom required for moral responsibility — been defended. One would expect hard determinism to have few proponents, given its apparent renunciation of morality. I believe, however, that the argument for hard determinism is powerful, and furthermore, that the reasons against it are not as compelling as they might at first seem. The categorization of the determinist position by 'hard' and 'soft' masks some important distinctions, and thus one might devise a more fine-grained scheme. Actually, within the conceptual space of both hard and soft determinism there is a range of alternative views. The softest version of soft determinism maintains that we possess the freedom required for moral responsibility, that having this sort of freedom is compatible with determinism, that this freedom includes the ability to do otherwise than what one actually will do, and that even though determinism is true, one is yet deserving of blame upon having performed a wrongful act. The hardest version of hard determinism claims that since determinism is true, we lack the freedom required for moral responsibility, and hence, not only do we never deserve blame, but, moreover, no moral principles or values apply to us. But both hard and soft determinism encompass a number of less extreme positions. The view I wish to defend is somewhat softer than the hardest of the hard determinisms, and in this respect it is similar to some aspects of the position recently developed by Ted Honderich. In the view we will explore, since determinism is true, we lack the freedom required for moral responsibility. But although we therefore never deserve blame for having performed a wrongful act, most moral principles and values are not thereby undermined.
Pereboom concludes:Pereboom distinguishes two libertarian positions, agent-causal and event-causal. While his agent-causal positions involve metaphysical freedom if not immaterial substance, his event-causal views assume that indeterminism is the direct or indirect cause of the action. He then traces decisions determined by character back to early character-forming events. Since they are always in turn either themselves determined, or at best indetermined, we can not be responsible for our characters either. This is the same regress as in Galen Strawson's Basic Argument.
Given that free will of some sort is required for moral responsibility, then libertarianism, soft determinism, and hard determinism, as typically conceived, are jointly exhaustive positions (if we allow the "deterministic" positions the view that events may result from indeterministic processes of the sort described by quantum mechanics). Yet each has a consequence that is difficult to accept. If libertarianism were true, then we would expect events to occur that are incompatible with what our physical theories predict to be overwhelmingly likely. If soft determinism were true, then agents would deserve blame for their wrongdoing even though their actions were produced by processes beyond their control. If hard determinism were true, agents would not be morally responsible — agents would never deserve blame for even the most cold-blooded and calmly executed evil actions. I have argued that hard determinism could be the easiest view to accept. Hard determinism need not be of the hardest sort. It need not subvert the commitment to doing what is right, and although it does undermine some of our reactive attitudes, secure analogues of these attitudes are all one requires for good interpersonal relationships. Consequently, of the three positions, hard determinism might well be the most attractive, and it is surely worthy of more serious consideration than it has been accorded. (p.272)
According to the libertarian, we can choose to act without being causally determined by factors beyond our control, and we can therefore be morally responsible for our actions. Arguably, this is the common-sense position. Libertarian views can be divided into two categories. In agent causal libertarianism, free will is explained by the existence of agents who can cause actions not by virtue of any state they are in, such as a belief or a desire, but just by themselves — as substances. Such agents are capable of causing actions in this way without being causally determined to do so. In an attractive version of agent-causal theory, when such an agent acts freely, she can be inclined but not causally determined to act by factors such as her desires and beliefs. But such factors will not exhaust the causal account of the action. The agent herself, independently of these factors, provides a fundamental element. Agent-causal libertarianism has been advocated by Thomas Reid, Roderick Chisholm, Richard Taylor, Randolph Clarke, and Timothy O'Connor. Perhaps the views of William of Ockham and Immanuel Kant also count as agent-causal libertarianism. In the second category, which I call event-causal libertarianism, only causation involving states or events is permitted. Required for moral responsibility is not agent causation, but production of actions that crucially involves indeterministic causal relations between events. The Epicurean philosopher Lucretius provides a rudimentary version of such a position when he claims that free actions are accounted for by uncaused swerves in the downward paths of atoms. Sophisticated variants of this type of libertarianism have been developed by Robert Kane and Carl Ginet.In a contribution to Essays on Free Will and Moral Responsibility, edited by Nick Trakakis and Daniel Cohen, 2008, Pereboom summarizes his case for "Hard Incompatibilism,"
Pereboom does not see that some event acausality must be a prerequisite for the agent causality he says might be a coherent description of free will. Genuinely random, uncaused events could contribute to According to the hard incompatibilist position I advocate, we would not have the sort of free will required for moral responsibility if determinism were true. We would also lack this sort of free will if indeterminism were true and the causes of our actions were exclusively states or events. If the causes of our actions were exclusively states or events, indeterministic causal histories of actions would be as threatening to this kind of free will as deterministic histories are. However, it might well be that if we were undetermined agent-causes — if we as substances had the power to cause decisions without being causally determined to cause them — we would then have this sort of free will. But although our being undetermined agent-causes has not been ruled out as a coherent possibility, it is not credible given our best physical theories. Thus we need to take seriously the prospect that we are not free in the sense required for moral responsibility. alternative possibilities for thoughts and actions. But Pereboom does not think alternative possibilities are needed for moral responsibility. He introduces a technical distinction between source and leeway incompatibilism that parallels John Martin Fischer's distinction between the actual sequence of events in a decision and any alternative sequences that depend on the existence of alternative possibilities. Fischer says the alternative possibilities may generate "flickers of freedom," But he seems convinced by Harry Frankfurt's thought experiments that show alternative possibilities are not needed to establish free will. Pereboom says:
In metaphysical terms, the sort of free will required for moral responsibility does not consist most fundamentally in the availability of alternative possibilities, but rather in the agent’s being the causal source of her action in a specific way. Accordingly, I advocate source as opposed to leeway incompatibilism.If indeterministic events merely generate alternative possibilities for action and in no way are the direct cause of actions as Pereboom fears, then agents can adequately determine their own decisions consistently with their character and values. Their character in turn is formed by all their earlier decisions and actions, which also were not pre-determined since the causal chain was broken by the existence of free alternative possibilities.
Pereboom's Four-Case ArgumentPereboom developed a well-known argument in defense of his hard-incompatibilist views, one which is a variation of the Manipulation Argument. The Four-Case Argument is only meant to enhance the intuition of lost agential control, in order to support the fundamental Determinism Objection in the standard argument against free will. Since the manipulators are only hypothetical and unreal, Pereboom uses them only to lend weight to the case for hard incompatibilism, which he defends whether or not determinism is true since he is agnostic. In Case 1 evil neuroscientists build a humanoid with remote radio controls in its brain and cause it to murder someone. In Case 2 they create a humanoid with a computer for a brain and program it to be a murderer. In Case 3 a real human is conditioned by rigorous behavior modifications to become a murderer. And in Case 4 the murderer is a normal human being who grew up in a world where physical determinism is true, so becoming a murderer is the end result of reason-responsive deliberations. Pereboom wants us to transfer our likely conclusions that the agent is not responsible in Cases 1-3 to Case 4, where ultimate causes for the agent's action are traceable to events beyond his control, what Pereboom calls the Causal History Principle. Pereboom's clever argument seems unlikely to convince confirmed compatibilists who already are comfortable with causal determinism. They know how to excuse moral responsibility in the case of real manipulations or other non-agential factors like coercion, addiction, hypnosis, etc.