Philosophers tend to tolerate a high degree of personal strangeness in one another. More specifically, they tend not to worry – at least explicitly or on the record – about whether the weird philosophical beliefs and the weird non-philosophical actions of a colleague might have a common source. The methodological norm rather is that ideas must stand or fall on their intrinsic merits; apart from anything else, this is probably good politics. Making the obvious psychological peculiarities of an author too operative a consideration within academic life might risk implicating an impractically large number of people. (And in that case, one probably wouldn’t trust most of them to apply the relevant criteria accurately anyway.) But this does make philosophy different from other areas of life, where we readily make informative connections, in both directions, between the strangeness of the person and the strangeness of his beliefs, often with a view to discrediting one or the other. 

Even in academic philosophy, however, individual eccentricity sometimes becomes too overwhelming to escape remark. In the case of Derek Parfit, one of the first things either a critic or admirer will acknowledge is just how odd a man he was. That his admirers apparently feel little misgiving in making this admission might be because, by the time he died in 2017, Parfit had safely established himself as among the most influential moral philosophers of his generation. In the first decades of his career, culminating in his 1984 book Reasons and Persons, Parfit made distinctive contributions to a locus of questions in practical philosophy concerning the nature of personal identity and the appropriate sphere of ethical concern. How far are we permitted to prioritise ourselves and our own interests in what we do? He is also widely recognised as the father of population ethics, a thriving area of research in contemporary moral philosophy. Parfit’s influence indeed extends outside of academia: Reasons and Persons is a revered text in the effective altruist movement.

He was also notoriously perfectionistic, obsessive, and a philosophical autodidact. Never satisfied for long with his own work, following Reasons and Persons, Parfit became increasingly preoccupied by more general questions concerning the nature of moral truth. He came to believe, as he told a colleague, that his life would have “been wasted” if he were not successful in establishing the objectivity of morality. In the process, he became ever more estranged from ordinary life, his everyday activities characterised by an exceptional mixture of self-indulgence and self-denial. Indeed, he valorised his philosophical task as a kind of duty arising from his ability to perform it. When asked by a nurse as he lay in a hospital bed “What do you do?”, he answered: “I work on what matters”. 

David Edmonds’s new biography, Parfit: A Philosopher and His Mission to Save Morality, is written on the assumption that its subject met with success in the mission alluded to in the subtitle – or, at any rate, that there was nothing fundamentally misguided about the way Parfit pursued its success. Edmond’s organising assumption is doubtless a requirement of any sympathetic biography of Parfit. Given the standard for success that he so explicitly defined for himself, and the shape that the rest of his life took as he attempted to meet it, a biography of Parfit sceptical of whether its protagonist satisfied his ambition would inevitably read as something between tragedy and farce.

Despite Edmond’s declared sympathy, his biography still has farcical elements. The book is largely an entertaining, and highly revealing, exercise in psychological portraiture by means of anecdote. Parfit, Edmonds tells us, would peddle in the nude on his exercise bike, reading philosophy; he would brush his teeth for hours, reading philosophy; every day he would eat the same breakfast of muesli and yoghurt and the same dinner of carrots, cheese, lettuce, and celery, to maximise his time for philosophy; he would make coffee using water straight out of the tap, to maximise his time for philosophy; he would take a mixture of vodka and pills every night to help him sleep, since he couldn’t stop thinking about philosophy. 

Edmonds cautions the reader that the last of these habits is not to be tried at home, but one finds oneself wondering what he makes of the others. Charming idiosyncrasies? Supererogatory sacrifices for the sake of philosophy? Each lens is initially tempting, but neither really works. Parfit’s habits were evidently not merely idiosyncratic; they had some sort of underlying unity. But, equally evidently, they were not sacrifices for the greater philosophical good either. No important work of philosophy has gone unwritten because its would-be author didn’t work on it while brushing his teeth. The natural diagnosis is that Parfit’s excessive self-deprivations were the manifestations of a more general psychological tendency, an apparent inability to pause and reflect, to properly control how he disposed of his time and energy: in short, an inability to self-regulate. 

Although not presented under this guise, Parfit’s difficulties with self-regulation are everywhere on display in Parfit. He was not just perfectionistic, he was by all appearances a paradigm of perfectionism. Parfit was “reluctant to commit anything to print unless he thought it incapable of improvement”. He put every manuscript through “dozens of drafts”. It seems possible that Parfit would simply never have published his first book, Reasons and Persons, were it not made clear to him that doing so was a condition of his remaining at All Souls. Once it was published, and Parfit received his reward of a permanent research fellowship, he did not publish another book for nearly 30 years, though he worked ceaselessly. 

The years-long process that brought Reasons and Persons to press was so stressful that Parfit’s hair turned white. He worried aloud that it might have “damaged his brain”. All the same, he appears to have been puzzled as to why other philosophers didn’t subject themselves to the same maddening ordeal. In fact, Parfit became famous for the copious comments he would produce in response to his colleagues’ draft manuscripts, often outstripping the original text in length. He simply didn’t know when to stop. When the philosopher Larry Temkin was on verge of sending his thousand-page monograph Rethinking the Good to press, Parfit emailed him with additional comments on every page. “Derek, I don’t want your comments! Enough’s enough!”, Temkin despaired. “But Larry, don’t you want your book to be as good as it can be?” Parfit asked. No, said Temkin: “I want my book to be done”. Temkin was not the only philosopher ultimately defeated by Parfit’s zeal for minute improvement; Shelly Kagan’s patience expired eventually too. “If you find a passage”, Kagan eventually communicated to Parfit, “where I literally contradict myself, I’ll deal with it, but I do not have the heart to make any further changes”.

Not for the only time in Parfit, a quality in the protagonist that at first glance indicates preternatural virtue risks overbalancing into something altogether more ambiguous, even unnerving. As Samuel Scheffler – another beneficiary-cum-victim of Parfit’s imposed editorial standards – recalled, Parfit’s industry for the sake of others was “literally astonishing”. The urge seems likely to have been rooted in Parfit’s difficulty in engaging with his colleagues’ work on its own terms. He could not, perhaps, imagine that their conception of the good, whether in ethics or in books on ethics, differed from his own. As the moral philosopher RM Hare tried to explain to him when Parfit encouraged Hare to delay publication of his own book Moral Thinking: “I don’t hope to write an ethics-book to end ethics-books”.

As Edmonds notes, Parfit’s own perfectionism often had the perverse effect of making his books worse than they might have been. The first edition of Reasons and Persons was full of small typographic and footnoting errors, the birthmarks of Parfit’s haphazardly demanding editorial regime. Well-honed material sat alongside improvised afterthoughts and appendices authored by others. A week before submission, Parfit was “on the brink of a breakdown”. “His brain could no longer process the text”, the words “swimming” before him on the page. In the end, certain “key editorial decisions” were taken by friends who interceded in the crucial final hours before submission, most notably the philosopher Susan Hurley. The first section of the book discussed different ways in which an ethical theory might be self-defeating; one wonders whether Parfit saw any connection to his own philosophical practice. 

Witnesses to Parfit’s long effort to bring his first book to publication worried that his behaviour was “crazy”, verging on the “neurotic”, that he was transforming himself into a “recluse”. Much to their growing dismay, publishers at Oxford University Press found that Parfit’s agonised perfectionism extended beyond philosophy to all aspects of book design. He obsessed over typeface and spacing. He frequently burst into tears in meetings. When the colours on the cover of the first printing of On What Matters were not exactly to his taste, he demanded the print-run be pulped and offered to pay for the new printing himself in an effort to get his way. Naturally, his taste constantly changed; the appearance of perfection never lasts. “I didn’t want to kill Derek”, one of Parfit’s OUP editors tells Edmonds. “But more than once I did think to myself that if he sends one more email, I’ll jump off a bridge!” 

Parfit’s apparent inability to realise what a nuisance he was making of himself points to a related further failure of self-regulation: Parfit’s obvious struggle to control his initial impulses when attempting to mindread, the task of ascribing mental states (such as knowledge, belief and intention) to others. A well-known default in mindreading is to generalise from one’s own case, making adjustments as needed for understanding differing perspectives. (Think of the young child who acts as if closing her eyes makes her invisible: such a child has not yet learnt to modify the default.) Parfit apparently instantiated that default to an unusual, sometimes comical, extent. When driving, his long-term partner Janet Radcliffe-Richards said, “he seemed to have no real idea of the need to make his intentions clear to other road users, or to try to read theirs”. (His favoured strategy was to pick a lane and treat other cars as obstacles to be avoided.) He was also visibly emotionally distressed by disagreement: across the board he felt a need for any difference in perspective to be quickly resolved. 

As he aged, philosophical disagreement increasingly distressed Parfit. In Q&As, he would obdurately respond to questions as if sifting through a mental rolodex of pre-approved defences of his position, in a manner that was often insensitive to the finer details of the question asked. If disagreement persisted, he could be brought to his knees – occasionally literally – as when, teaching at Harvard in 2010, he fell to the ground “pleading with the class” to accept his objectivist meta-ethical position.  

Particularly distressing to Parfit was disagreement with philosophers he admired, above all Bernard Williams, who along with Parfit was one of the outstanding figures of English moral philosophy. Unlike Parfit, Williams was urbane, self-possessed and inclined to moral anti-realism. Parfit’s increasingly desperate and emotionally one-sided run-ins with Williams become one of the comical leitmotifs of Edmond’s book. The fact that Williams died without having come to accept the objectivity of morality, as Parfit would have liked him to, could, even when it occurred to him years later, reduce Parfit to tears. Parfit would agonise over Williams’s misguidedness to anyone, be they philosopher or innocent bystander, who would listen. He would chase Williams after talks at Oxford in fits of persuasive fervour, into the rain, up to the older man’s car, still “pounding an arm on the bonnet [as] Williams wound up the window and drove off, leaving his harasser standing there, drenched and bedraggled”. When All Souls hosted a commemorative dinner after Williams’s death in 2003, Williams’s widow found she had to comfort a weeping Parfit. 

Parfit was quick to cry, but less disposed to other forms of negative affect. As Edmonds remarks, Parfit was “remarkable in that he had no feelings of vengeance even towards those who had genuinely wronged him”. It was not that he successfully inhibited such reactions but that he seemed not to experience them in the first place. The work of his older Oxford colleague Peter Strawson on reactive attitudes like resentment left Parfit mystified. The philosophy of punishment seemed to him a contemptibly misconceived sub-discipline. Watching archival footage of Hitler merrily performing “a little jig” upon hearing of the French surrender to the Nazis in 1940, Parfit felt not contempt, but instead little more than a residue of recognition that “at least something good came out of the German victory”. This failure to marshal affective responses seems to have registered even with Parfit as a deficit of sorts. When Saddam Hussein invaded Kuwait, Parfit seized on it as an opportunity to attempt “to self-ignite the full range of reactive attitudes experienced by ordinary people”, immersing himself in the news coverage. Still, he found “he could not summon up any hatred”. 

Parfit’s absence of negative affect was connected to a much more general trouble he had, at least in his practical life, in appropriately tracking distinctions of importance. Whatever was made salient to him in a context, he treated as deeply important. According to Edmonds, when atrocities of the past were unexpectedly brought to his mind, Parfit could burst into tears, in effect reacting as if they were happening then and there. At dinner with the philosopher Victor Tadros in a Lebanese restaurant in Oxford, discussion turned to the casualties of the First World War. “Suddenly, in the middle of that discussion, Derek started to cry, really quite a bit. He was crying at the sadness of all of those lives ended prematurely in the war. I wasn’t quite sure what to make of this.”  

Conversely, whatever was not imminently salient to him was of marginal concern. Larry Temkin recounts praising a beautiful photograph in Parfit’s office of the Radcliffe Camera, which Parfit had spent thousands of pounds having painstakingly edited to perfection. His admiration prompted Parfit later to bring the photograph to the United States as a gift for Temkin: he transported it crumpled up at the bottom of his suitcase. Similarly, once the final version of On What Matters was published, he never again commented on any blemishes in its appearance. Even the last-minute changes that were made to Reasons and Persons by Susan Hurley seemed not to bother him after a moment, despite the obsessive control he was so prone to exercising. Perfectionism waxes and wanes with the caprices of attention.  

In the final chapter of Parfit, having provided so much evidence of Parfit’s psychological limitations, Edmonds explicitly raises the question of whether he may have been autistic. One complication for that diagnosis, discussed by Edmonds, is that when young, Parfit hardly fit the prototype of autism: at twelve, he was a stylish writer, exhibiting mature facility with analogy and metaphor; at Eton, he was outgoing, with sophisticated interests, popular, “even cool”; an early girlfriend from Oxford insists that he was “not at all weird”. Even in later life, Parfit remained capable of ordinary social interaction. At least when distracted from his philosophical preoccupations, he could be funny and charming: in a word, normal. In any case, whether or not Parfit’s many difficulties in self-regulation and mindreading reflect a form of autism, it must be acknowledged that they really were difficulties. Independently of the content of a diagnosis, that is enough for the question of how they interacted with his philosophical outlook to arise.

That something interesting can be said about the relation between a philosopher’s character and his work is typically a background assumption of philosophical biography. However, in many contemporary cases, as with academic mathematicians or scientists, any hope of fruitful connections can seem quite limited. Sometimes, that is because a philosopher’s theoretical work is too far removed from common sense for anything very accessible to be said about it. Other times, it is because the philosopher is altogether too normal. However, there are also more interesting cases—in particular, of philosophers who at once exhibited clear psychological pathologies and explicitly denied the reality or importance of various common-sense distinctions. Kant is perhaps an example. Wittgenstein is a more recent paradigm. In such cases, it is natural to ask if limitations in their psychology might explain why their philosophy took the form it did.

Such readings need not be critical, though it is tempting to think that they should sometimes be. Against this thought, and rather strikingly when one comes to think of it, stands a much more widespread cultural predisposition to attribute a kind of privileged access to the maladjusted mind. For example, Wittgenstein’s disciples tend to treat his tortured and anti-social qualities as somehow evidence in favour of his pronouncements. A common idea seems to be that the weirder one’s way of thinking, the more likely one is to get things right, for the truth could not possibly be publicly available. (Hallucinogens no doubt derive some of their appeal from a similar misconception.) This is to get things exactly the wrong way around. When presented with a philosopher whose life was radically limited and whose philosophy was commensurately dismissive of apparently central parts of reality, a more realistic default expectation is that the narrowness of his perspective simply obscured important features of ordinary life from him—that he was blind to facts that most people access without trouble, rather than having the philosophical far-sightedness to somehow see past them.

To be clear, Parfit was no Wittgenstein. On the contrary, Parfit was often compassionate, excessively generous with his time, and had an uncomplicated love for his subject and interest in the work of other philosophers. In a quite counter-Wittgensteinian manner, his opening gambit with any newly elected Prize Fellow at All Souls would be to try to persuade them to abandon their subject and switch to philosophy given it was obviously so much more important. Nor in general did Parfit’s philosophy consist in the sorts of radically sceptical claims that might appropriately be regarded as a reductio of any argument for them. Nevertheless, there are ample ways in which Parfit’s psychological oddities, as surveyed by Edmonds, pollute his theorising.  

Arguably, they manifest even at the level of form. Parfit’s philosophy is striking for its total absence of logical symbols, indicating one clear-cut way in which he was handicapped by his unwillingness or inability to overcome certain initial impulses. In this case, the cause seems to have been anxiety or fear about lack of success. Edmonds recalls that Parfit reported having “a phobia of logical symbols”, as well as of mathematics generally. In fact, as an undergraduate Parfit was so averse to formal notation that the threat of encountering it was sufficient to prevent him from studying PPE (Philosophy, Politics and Economics) as an undergraduate at Oxford, something that to anyone familiar with the demands of that degree will suggest the rather debilitating extent of the phobia. Edmonds points out that there is something of a mystery here: Parfit was not bad at maths at Eton, and his subsequent protestations reek of post-hoc rationalisation. All the same, later in his career he would insist that technical results in population ethics be explained to him, if at all, “in English without formal symbols”. Whatever the origin of Parfit’s arithmophobia, the aversion would never have ossified if he had challenged himself earlier. Its result was that Parfit cut himself off from some of the most powerful tools in the modern philosophical repertoire—and from engaging with any contemporary work which made essential use of those tools. 

Another component of Parfit’s idiosyncratic psychology that works its way onto the page is his obvious difficulty in managing disagreement. Now, Parfit is not unique among philosophers in disliking disagreement. The philosophical industrial complex supports an army of research programmes—relativist, expressivist, contextualist, and so on—dedicated to theorising away the reality of disagreement. But Parfit’s acute aversion to disagreement radically infects his second book, On What Matters. The book’s first half consists in an extended attempt to demonstrate that the ethical traditions of utilitarianism, Kantianism and contractualism ultimately converge: on the best way of understanding each, Parfit argues, they do not really disagree. On the face of it, Parfit’s view is deeply implausible. After all, standardly conceived, Kantianism implies that it is always forbidden to lie, while standardly conceived, consequentialism implies that it is often permissible to lie. Parfit’s strategy is to conceive each of each of the traditions idiosyncratically, and, through a dialectic of idealisations and qualification, shape them into putatively consistent forms. The manifest danger in subjecting a philosophical idea to such an editing process is that the result will deprive it of any distinctive interest whatever. 

The second half of On What Matters is dedicated to meta-ethics: the area of philosophy concerned with the nature of moral facts and properties, moral knowledge, and moral language. Over time, Parfit grew increasingly preoccupied with meta-ethics. As Edmonds emphasises, Parfit became gripped by worry that if he could not establish the truth of a specific form of moral realism, his life would have been “wasted”. But meta-ethics was also an area of philosophy for which his rejection of formal tools and obsession with morality left him particularly ill-equipped. For meta-ethics is broadly continuous with general metaphysics, general epistemology and the general philosophy of language, and so nearly impossible to do well in ignorance of the rest of philosophy, not least some quite technical philosophy. Important parts of the discussion of meta-ethics in On What Matters reflect Parfit’s ignorance of general developments in philosophy which had escaped his monomaniacal attention. His attempt to engage with a form of anti-exceptionalist realism about morality, according to which facts and properties expressed in moral terms might turn out to be identical to facts and properties expressed in non-moral terms, betrays a lack of familiarity with the extensive literature on non-trivial identities (a central topic in analytic philosophy since Frege) and often lapses into dogmatism as a result. 

As one might expect of someone with Parfit’s affect and temperament, reflection led him to marginalise various important common-sense distinctions and instead replace them with highly-theorised alternatives. Some of his best-known work was on the nature of personal identity and its practical consequences. In part by use of fantastical thought experiments, Parfit argued that personal identity was not “what mattered” in evaluating the goodness or badness of potential outcomes or to questions of moral responsibility. By way of illustration, consider a standard teletransporter case: a subject NN steps into a teletransporter on Earth; NN’s body is vaporised; some moments later, an intrinsic duplicate of NN materialises on Mars. Plausibly, NN dies in this process: it is merely a clone of NN who steps out the other side of the device. Also plausibly, whether or not NN dies is decisively relevant to whether NN should have stepped into the device: it matters for NN whether the person who materialises on Mars is in fact the same person.

Parfit accepted the first claim, motivating it by consideration of ingenious variations on the original case, but he rejected the second. In effect, he concluded that what mattered was whether people sufficiently psychologically connected to one lived on, not whether one lives on oneself. That in turn made room for the potentially reassuring thought that, even in non-science-fictional cases, whether one survives is not, in itself, what matters. Instead, what really matters is whether anyone to whom one was relevantly psychologically connected survives. Further, Parfit combined this idea with the view that other times are just as real as other places. As a piece of metaphysics, such a conception of time is not idiosyncratic. However, quite originally, Parfit thought that it had the normative consequence that death mattered less, reasoning that people who are alive at other times were therefore like people who are alive in other places. He naively imagined that this analogy would console others too, writing to Joyce Carol Oates after her first husband died, in a version of a message that he sent to at least one other friend: “When someone I loved died I found it helpful to remind myself that this person was not less real because she was not real now, just as people in New Zealand aren’t less real because they aren’t real here”.

Clearly, Parfit’s surprising claims about the significance of death merit serious consideration, and are not to be dismissed on the basis of psychological speculation alone. All the same, supposing for the sake of argument that Parfit’s claims are mistaken (Oates, Edmonds reports, “compared [Parfit’s suggestion] to trying to console an amputee that his leg was still real and existed in New Zealand”), it is not altogether surprising that Parfit would have reached such misjudgements about distinctions of common-sense importance. Indeed, Edmonds notices the tension between Parfit’s theory and even his own everyday practice. Parfit wrote that before arriving at his theory life had seemed to him “like a glass tunnel, through which I was moving faster every year, and at the end of which there was darkness. When I changed my view, the walls of my glass tunnel disappeared. I now live in the open air”. This remarkable account is not one easily reconciled with the psychology of Parfit’s own working life, in which he was often frantically motivated by the fear and finality of his own death.

Parfit’s dedication to defending a narrow range of counterintuitive conclusions in his philosophy makes him the archetype of a certain kind of philosopher. But it seems likely he would have been a better philosopher had he spread his interest more widely and better controlled his instinctive fears and dislikes—from logical notation to death and disagreement.

Part of the problem, as suggested, owes to his apparent lack of internal regulation. But another factor was undoubtedly his environment. In particular, with the exception of the period in which All Souls postponed his appointment to a permanent research fellowship until he produced a book, the College played for Parfit what can only be described as the role of an enabler. First, he was admitted as a Prize Fellow in philosophy, having never been trained in the subject; his admission guaranteed that he never would be. Later, his post liberated him from normal academic responsibilities, particularly tutorials with undergraduates. And once granted a permanent post, he was enabled to do more or less anything he liked: in Parfit’s case, that turned out to be working as a socially-isolated obsessive who frantically wrote and rewrote an ultimately unsuccessful book for 30 years – a fate one would only wish on one’s worst enemy. Such freedom from constraint is no doubt just what Parfit wanted. It was the opposite of what he needed.

It is perhaps on the issue of Parfit’s relationship with All Souls that Edmonds exhibits his greatest complacency concerning his subject. For one thing, he treats All Souls’ decision to impose preconditions on Parfit’s appointment to a permanent research post as quite unwarranted. When, if at all, Reasons and Persons would have been published if not for that decision remains a good question. More strikingly, in discussing the question of Parfit’s potential autism, Edmonds observes that Parfit’s behaviour became increasingly pathological from around the time he was given a permanent position at All Souls. Edmond’s upbeat gloss on this coincidence is that Parfit “was no longer required to be what he was not”, a reflection which leads him to dismiss the diagnostic issue as ultimately moot, since “Parfit did not suffer in the academic institution in which he spent almost all his adult life … on the contrary, he thrived”. Again, Parfit would no doubt have seen it that way. 

As a biography, it is tempting to think of Parfit as an unintentional success. David Edmonds vividly represents his subject, with much detail that sheds light on the relation between his life and work, though the overall effect cannot possibly have been what he intended to bring about. Knowledge of Parfit’s life certainly informs how one might come to think of his philosophy. Without it, one might unthinkingly have taken Parfit’s dutiful submission to the pursuit of a narrow range of ethical question to be a paradigm of discipline. However, seen another way, he was a man out of control—and out of touch with a great deal of what matters.

Daniel Kodsi is a lecturer in philosophy at Magdalen College, Oxford, and editor of The Philosophers’ Magazine. John Maier is reading for a DPhil in Philosophy at Balliol College, Oxford, and a leader writer for The Times.