What's Wrong With Determinism? Review of "Determined" by Robert Sapolsky

Tom Clark
Book Title: 
Determined: A Science of Life Without Free Will
Book Author: 
Robert M. Sapolsky

Behavioral biologist Robert Sapolsky shows why causal determinism is key to understanding ourselves and how its acceptance can contribute to moral progress.

What's Wrong With Determinism?

review of

Determined: A Science of Life Without Free Will

by Robert M. Sapolsky


Free will in opposition to determinism

When asked, most folks in most circumstances can give a plausible account of why they decided and acted as they did. They will cite the factors that played a role in the decision, what we can call its determinants, whether these were desires, available options, external constraints, advice they got, you name it. If asked to explain why you’re reading this review, you’ll come up with various reasons and causes that led you here, now.

This commonsensical observation about how we explain ourselves to ourselves and others nevertheless collides with one common conception of free will: that the determinants we might cite in explaining a choice aren’t fully explanatory. In addition, it’s often thought that we have a capacity or ability to select among options in a way that transcends the causal role of those determinants. This ability – what’s sometimes called in philosophical literature contra-causal or libertarian free will – makes it the case that even given all the factors in play we could have chosen otherwise in an actual situation just as it transpired. We are therefore buck-stopping, ultimate authors of our actions and ourselves whose nature and behavior can’t be fully traced to antecedent conditions: we are uncaused or ultimately self-caused causers – in philosophical parlance, a causa sui.

That many harbor this intuition about human agency is why in debates about free will it is commonly contrasted with determinism, the idea that events, including human behavior, can in principle (often not in practice) be fully accounted for by their presumptive determinants. Determinism has it that there is no causally untethered decider or actor in play when explaining a choice, so it couldn’t have turned out otherwise given its causes. For you not to be reading this review right now, some factor that explains your reading it would have had to have been different. If free will is widely conceived as being opposed to determinism[1], it isn’t surprising that the latter is seen as a threat to responsibility, meaning, creativity, rationality, and other desiderata tied to our core notion of agency. If we’re fully caused to be who we are and do what we do, then it seems we’re merely biological robots, acting out a pre-ordained script; we don’t make real choices for which we might be praised or blamed.

Could you have done otherwise?

This is why Robert Sapolsky’s book Determined: A Science of Life Without Free Will, is likely to ruffle more than a few feathers (although it will do so very entertainingly, see below). Following up on his earlier work Behave, Sapolsky, a behavioral biologist, is intent on making it clear to anyone who will listen that there is no escaping determinism if we’re serious about understanding ourselves: understanding how we got to be the exact persons we are and why our intentions and choices arise as they do. Moreover, as he takes pains to point out, indeterminism or randomness doesn’t help the cause of agency. After all, as deciders we want to determine our choices, not have them be subject to factors we don’t control. Strangely enough, therefore, determinism, construed commonsensically as the existence of reliable causal, and more broadly, explanatory connections between our desires, decisions, actions, and their effects on the world, seems a necessary condition of genuine agenthood. We really make choices, just not undetermined or arbitrary ones.[2]

But the fact remains that Sapolsky’s thesis will likely find little immediate acceptance. Most folks will cling tightly to the idea that they could have chosen otherwise in an actual situation with all conditions, including their reasons and desires, exactly as they were. Philosophers call this the unconditional ability to do otherwise, as contrasted with the conditional ability in which, had some condition been otherwise, a different choice might have ensued given that we’re behaviorally flexible.[3] It isn’t difficult to see that exercising the unconditional ability would render a choice unintelligible and arbitrary by sidelining your very own reasons as the final determinants. Try this: If you suppose you could have chosen otherwise on a specific occasion, why didn’t you? Answer that question and you’ll be led to an essentially, albeit only approximately, deterministic explanation of your behavior in terms of the reasons and causes that were in play (approximate because we’re not omniscient about our own behavior, plus there might be inherent indeterminacy in nature). To have chosen otherwise something relevant to your choice would have had to have been otherwise. To want to be free to choose independently of the factors that in hindsight explain a choice, many of which have to do with who we are as specific persons, seems irrational, even though of course we sometimes wish we had chosen otherwise. The determinants of voluntary, deliberate action are thus the necessary currency of agency, not a threat to it. And what applies to your choice applies to you: in principle you’re explicable in terms of a very complex concatenation of causal factors, genetic and environmental, some of which would have had to have been otherwise for you not to be the exact person you are, doing what you’re doing right now.

The causal story

Sapolsky elucidates the determinants of behavior in encyclopedic detail, working back from your current intention to its associated brain state, then to all factors that explain you, your brain, and your intention as an emergent property of what neurons do. There are reams of footnotes, endnotes, and citations of scientific studies. His aim is to convince you that there is no place – none! – for an uncaused intervenor, for instance at the level of brain processes, to play a role in choice making. As far as we can scientifically tell, it’s causal mechanisms at whatever level you care to look, neural, bodily, environmental, or social, all seamlessly interlinked over time and place. Given the complexity of causal interactions and our limited knowledge of them, we usually can’t precisely predict or explain someone’s behavior. But the fact that our explanations and predictions are therefore often probabilistic, not algorithmic, is no reason to posit the causa sui.[4]

Sapolsky’s relentless documentation of the causal story is leavened by a wry, irreverent, and sometimes hilarious self-skepticism. Although his expertise is obvious, he makes sure we understand that he’s just the fallible messenger, so please not to shoot. And he is profusely apologetic for dragging us through the messy mechanics of how the brain governs behavior, and how our circumstances, genetic and environmental, shape us and our brains. He advises us not to underline or take notes, but simply absorb the big mechanistic picture. All told, the tone is like having a beer (or several) with a world-weary apostle of determinism who knows what he’s up against but slogs on, hoping that you’ll see the light (he says you likely won’t, not completely anyway). But slogging has never been so entertaining, and all the details are there if you care to look. If you don’t, there are frequent ordinary language summaries of the main points.

Living in light of determinism

Having argued in the first half of the book that there’s no ghost in the machine, that we are, even in the exercise our highest, most rational capacities, traceable in principle to conditions we couldn’t have controlled, the second half covers how we are to live with determinism. The psychological ideal, which Sapolsky ruefully admits he can’t attain, would be one of unbounded compassion and forbearance, of eschewing reactive attitudes such as anger, disdain, self-blame, and self-aggrandizement premised on the idea of contra-causal, libertarian free will: that we are essentially self-created and thus deeply deserve our accomplishments or failures. But even if we can’t completely divorce ourselves from our reactive attitudes (not a good idea in any case)[5], we should, he says, completely rethink core notions of blame, deservingness (desert), and moral responsibility. He hopes this radical shift in our concept of agency will translate into behavioral change, both personal and social.[6] The latter would involve policy reforms such as abandoning retributive punishment and addressing the conditions that are causally responsible for crime, addiction, mental illness, and other barriers to personal and social well-being. He points out that such a transformation would continue a centuries-long humanitarian evolution in our responsibility practices related to wrong-doing and behavioral disorders: we no longer burn people at the stake, crucify them, or hang them in public to satisfy calls for justice. We no longer blame and punish people for being autistic, schizophrenic, or bipolar. Accepting determinism would be the culmination of naturalizing our self-conception in accord with science: dropping the immaterial soul and its contra-causal freedom. Such naturalization subtracts supernatural and logically incoherent justifications for acting on our naturally evolved penchant for punishment; it thus can mitigate our reactive attitudes, in particular moral anger (see note 5).

What’s wrong with libertarianism and compatibilism

Sapolsky has two fights on his hands: one with free will libertarians who maintain that we really do have the unconditional ability to do otherwise (many regular folks probably fall in this camp, along with a  small minority of philosophers and scientists), and the other with compatibilists (the majority of philosophers, probably not the folk), who maintain that free will and moral responsibility are compatible with determinism and whatever randomness might exist in nature. He decisively dispatches libertarians by adducing the science behind behavior mentioned above: if you take a naturalistic, evidence-based approach to understanding the world, there really is no place to find the causa sui (if you don’t, then this book likely won’t make a dent in your beliefs about free will). Moreover, in one of his many detailed sub-investigations Sapolsky can discover no neural mechanism that corresponds to the unconditional ability to do otherwise, despite the claims of libertarian philosophers and neuroscientists, e.g., Robert Kane and Peter Tse, that there is such a mechanism.[7]

The fight with compatibilists isn’t about determinism; compatibilists agree that we and our choices are in principle explicable by various determinants, not the causa sui. It’s rather about the relative importance assigned to determinism and its implications for moral responsibility and other beliefs, attitudes, and social practices informed by our conception of agency. Sapolsky argues that compatibilists tend to ignore the causal story behind an individual in order to fix our attention on agents and their capacities for rationality and reasons-responsiveness, capacities that compatibilists argue justify holding each other morally responsible.[8] Most of us are capable in these respects to varying degrees, but by downplaying determinism and the causal story, what Sapolsky calls taking the ahistorical stance, compatibilists in effect block access to the psychological and practical benefits of putting determinism front and center: increased compassion and more attention paid to the conditions that thwart human flourishing. Due to factors beyond our control too many of us end up with the short end of the stick when it comes to health, education, social skills, and employability. Sapolsky is especially critical of compatibilist Daniel Dennett, who has claimed that “luck averages out in the long run”. He responds in characteristically plain-spoken style:

No it doesn’t. Suppose you’re born a crack baby. In order to counterbalance this bad luck, does society rush in to ensure that you’ll be raised in relative affluence and with various therapies to overcome your neurodevelopmental problems? No, you are overwhelmingly likely to be born into poverty and stay there. Well then, says society, at least let’s make sure your mother is loving, is stable, has lots of free time to nurture you with books and museum visits. Yeah, right; as we know your mother is likely to be drowning in the pathological consequences of her own miserable luck in life, with a good chance of leaving you neglected, abused, shuttled through foster homes. Well, does society at least mobilize then to counterbalance that additional bad luck, ensuring you live in a safe neighborhood with excellent schools? Nope, your neighborhood is likely to be gang-riddled and your school underfunded.

In arguing against compatibilists, Sapolsky engages with the philosophical literature, citing skeptics about free will and moral responsibility such as Neil Levy, Gregg Caruso, Derk Pereboom, and Sam Harris (see references below). Such backup suggests he is not completely crazy to think that a robust appreciation of determinism, and therefore the sheer contingency of our formative circumstances, should force reconsideration of our conceptions of credit, blame, reward, and punishment. Compatibilists generally suppose we can keep our current system of moral responsibility more or less as it stands; that, for example, rational wrong-doers who act intentionally deserve punishment independently of any forward-looking benefits – the definition of retribution. Incompatibilists such as Sapolsky and his allies say no: given determinism, such desert lacks foundation and therefore the criminal justice system in the US, committed to retributive punishment, needs radical reform. More broadly, we should question the idea of a just world: that people generally get what they deserve since they could, and should, have overcome their circumstances using their unconditional ability to have done otherwise. But no one has that ability, so your good or bad character or fortune, and the current exercise of your good or bad judgment, is ultimately traceable to circumstances that were not under your control.

Reassurances about determinism

All this is well taken in my view, but compatibilists also have a point: agency and responsibility must be compatible with determinism (and any indeterminism that plays a role in behavior, which can’t add to authorship or control).[9] In coming to terms with determinism and the science behind it, what Sapolsky urges on us, we shouldn’t deny the reality of our own causal powers or of our own local control.[10] We don’t need to be exceptions to cause and effect, or ultimately self-caused, to be potent causers and controllers in our own right, and to be held responsible in a forward-looking way that helps to shape behavior for the good. Reliable causal relations between desire, deliberation, intention, and action need to be in place for us to be effective agents, and as noted above any disconnection from the causal context would make the exercise of our will a mystery, not our own doing. Seen in this light, determinism is not a bitter pill, not a derogation of human dignity or power, but the very key to agency. Even if their defense of desert-based moral responsibility fails, compatibilists have got this much right.

Sapolsky reassures us that fostering disbelief in libertarian freedom will not result in moral anarchy. Just as atheists can be good without God, so too can skeptics about the unconditional ability to do otherwise. But he is circumspect about success in converting free will believers given the presumption against determinism. Fortunately, he is not alone in this quest. Besides the work of allies mentioned above (Levy, Caruso, Pereboom, and Harris) challenging the existence of contra-causal free will has become almost a commonplace in secular scientific circles as well as a topic of articles in the mainstream press.[11] And in the behavioral health community talk about the social determinants of health, addiction, and crime is now standard.[12] To what extent and how quickly might a determinist perspective spread among regular folk? Acceptance of determinism will depend in large part on how it’s portrayed: not as an affront to a realistic conception of autonomy, but its basis. Not as fatalism, but as key to effective action informed by greater knowledge of the causal and explanatory relations that govern behavior. Not as a blanket excuse, but as an evidence-based view of wrongdoing that will lead to a more humane criminal justice system. Not as universally true, given that indeterminism might exist in nature, but as a pragmatically useful perspective that affords us greater compassion and control, a secure basis on which to understand ourselves in service to human and planetary flourishing.

Determinism is unlikely to go viral any time soon given its image as the enemy of freedom, but that perception may shift as the incoherence of libertarian free will becomes apparent, and as the evidence for our complete inclusion in the causal order grows. Sapolsky has marshalled a compelling case for such inclusion, presented it with unconventional flair, and shown the practical and ethical advantages of taking determinism to heart. His persistence in seeing Determined to completion – a prodigious undertaking – is much to be congratulated, although he would disavow deserving any such praise. Even if he’s right about that, we’re still lucky to have him.

TWC, 9/16/2023


Caruso, G. 2021. Rejecting Retributivism: Free Will, Punishment, and Criminal Justice. Cambridge University Press.

Clark, P. B. 2023 (1963). The Compatibility of Free Will and Determinism. Opus/Politics and Prose.

Feldman, G., & Chandrashekar, S. P. (2018). Laypersons’ Beliefs and Intuitions About Free Will and Determinism: New Insights Linking the Social Psychology and Experimental Philosophy Paradigms. Social Psychological and Personality Science9(5), 539–549.  

Harris, S. 2012. Free Will. Free Press.

Levy, N. 2015. Hard Luck: How Luck Undermines Free Will and Moral Responsibility. Oxford University Press.

Pearl, J. 2018. The Book of Why. Basic Books.

Pereboom, D. 2001. Living Without Free Will. Cambridge University Press.

Pinker, S. 2008. “Fear of Determinism” in Are We Free? Psychology and Free Will, John Baer, James C. Kaufman, and Roy F. Baumeister, editors. Oxford University Press.

Nadelhoffer, T., Siyuan Yin & Rose Graves (2020) Folk intuitions and the conditional ability to do otherwise, Philosophical Psychology, 33:7, 968-996, DOI: 10.1080/09515089.2020.1817884

Waller, B. 2011. Against Moral Responsibility. MIT Press.



[1] Definitions of free will vary, so it’s important to specify what we mean by “free will” prior to claiming it exists or doesn’t. The intuition that we have the contra-causal variety (at odds with determinism) seems widespread, see Feldman et al. 2018.

[2] In a book chapter titled “Fear of Determinism,” Steven Pinker puts it this way: “The experience of choosing is not a fiction, regardless of how the brain works. It is a real neural process, with the obvious function of selecting behavior according to its foreseeable consequences. It responds to information from the senses, including the exhortations of other people. You cannot step outside it or let it go on without you because it is you.”

[3] See Nadelhoffer et al. 2020 for evidence that many folks suppose they have the unconditional ability to do otherwise. See also note 6 below. For a careful analysis comparing the two senses of the ability to do otherwise, see Ch 4, “Determinism and Avoidability” in Clark, 2023 (1963).

[4] On how progress is being made in understanding causal relations and mathematically formalizing causal inference, see Judea Pearl’s The Book of Why: The New Science of Cause and Effect.

[5] Losing our capacity for say, moral anger, altogether would make us easy marks for cheaters and wrongdoers, so isn’t advisable. But determinism can mitigate moral anger by eliminating the deeply deserving libertarian agent, thus reducing the chances of anger overshooting its naturally evolved function. On this point see my critique of philosopher John Martin Fisher’s proposal to adopt what he calls semiretributivism.

[6] Determinism, as Sapolsky points out, is no bar to change. That you couldn’t have done otherwise in an actual past situation doesn’t imply that you’re fated to act the same way in a future similar situation, given what you’ve learned from experience. Social progress too is perfectly compatible with determinism: knowing the determinants of beliefs, attitudes, and behavior is an aid, not an impediment, to implementing more enlightened policies.

[7] For philosophical and neuroscientific defenses of libertarian free will, see Robert Kane’s The Significance of Free Will and Peter Tse’s The Neural Basis of Free Will.

[8] Along the same lines, my review of Bruce Waller’s book Against Moral Responsibility is titled Singling out the agent.

[9] See Clark 2023 (1963) for a carefully argued case for compatibilism.

[10] Sapolsky sometimes seems to suggest we don’t have local, proximate control over our own behavior: “We are not captains of our ships, our ships never had captains.” “’There, I just decided to pick up this pen – are you telling me that was completely out of my control?’  Yes, I am.” We don’t have ultimate, contra-causal control, but I imagine he’d agree that the brain is more or less in control of the body (with lots of reciprocal influence of course). If as physical beings we are basically brains in bodies, then we are in control of what we do, even if we are entirely determined in how that control is exercised.

[11] See for example There’s No Such Thing as Free Will (2016) in The Atlantic and The Clockwork Universe: Is Free Will an Illusion? (2021) in The Guardian.

[12] See for example this explainer on the social determinants of health (SDOH) from the Healthy People 2030 initiative.