Derek Antony Parfit (; 11 December 1942 – 2 January 2017) was a British philosopher who specialised in
personal identity
Personal identity is the unique numerical identity of a person over time. Discussions regarding personal identity typically aim to determine the necessary and sufficient conditions under which a person at one time and a person at another time ...
,
rationality
Rationality is the quality of being guided by or based on reason. In this regard, a person acts rationally if they have a good reason for what they do, or a belief is rational if it is based on strong evidence. This quality can apply to an ab ...
, and
ethics
Ethics is the philosophy, philosophical study of Morality, moral phenomena. Also called moral philosophy, it investigates Normativity, normative questions about what people ought to do or which behavior is morally right. Its main branches inclu ...
. He is widely considered one of the most important and influential
moral philosopher
Ethics is the philosophical study of moral phenomena. Also called moral philosophy, it investigates normative questions about what people ought to do or which behavior is morally right. Its main branches include normative ethics, applied ethics ...
s of the late 20th and early 21st centuries.
Parfit rose to prominence in 1971 with the publication of his first paper, "Personal Identity". His first book, ''
Reasons and Persons
''Reasons and Persons'' is a 1984 book by the philosopher Derek Parfit, in which the author discusses ethics, rationality and personal identity.
It is divided into four parts, dedicated to self-defeating theories, rationality and time, personal ...
'' (1984), has been described as the most significant work of moral philosophy since the 1800s.
His second book, ''
On What Matters'' (2011), was widely circulated and discussed for many years before its publication.
For his entire academic career, Parfit worked at
Oxford University
The University of Oxford is a collegiate research university in Oxford, England. There is evidence of teaching as early as 1096, making it the oldest university in the English-speaking world and the second-oldest continuously operating u ...
, where he was an Emeritus Senior Research Fellow at
All Souls College
All Souls College (official name: The College of All Souls of the Faithful Departed, of Oxford) is a constituent college of the University of Oxford in England. Unique to All Souls, all of its members automatically become fellows (i.e., full me ...
at the time of his death. He was also a visiting professor of philosophy at
Harvard University
Harvard University is a Private university, private Ivy League research university in Cambridge, Massachusetts, United States. Founded in 1636 and named for its first benefactor, the History of the Puritans in North America, Puritan clergyma ...
,
New York University
New York University (NYU) is a private university, private research university in New York City, New York, United States. Chartered in 1831 by the New York State Legislature, NYU was founded in 1832 by Albert Gallatin as a Nondenominational ...
, and
Rutgers University
Rutgers University ( ), officially Rutgers, The State University of New Jersey, is a Public university, public land-grant research university consisting of three campuses in New Jersey. Chartered in 1766, Rutgers was originally called Queen's C ...
. He was awarded the 2014
Rolf Schock Prize
The Rolf Schock Prizes were established and endowed by bequest of philosopher and artist Rolf Schock (1933–1986). The prizes were first awarded in Stockholm, Sweden, in 1993 and, since 2005, are awarded every three years. It is sometimes conside ...
"for his groundbreaking contributions concerning
personal identity
Personal identity is the unique numerical identity of a person over time. Discussions regarding personal identity typically aim to determine the necessary and sufficient conditions under which a person at one time and a person at another time ...
, regard for
future generations
Future generations are Cohort (statistics), cohorts of hypothetical people not yet born. Future generations are contrasted with current and past generations and evoked in order to encourage thinking about intergenerational equity. The Moral agenc ...
, and analysis of the structure of moral theories."
Early life and education
Parfit was born in 1942 in
Chengdu
Chengdu; Sichuanese dialects, Sichuanese pronunciation: , Standard Chinese pronunciation: ; Chinese postal romanization, previously Romanization of Chinese, romanized as Chengtu. is the capital city of the Chinese province of Sichuan. With a ...
, China, the son of Jessie (née Browne) and Norman Parfit, medical doctors who had moved to
Western China
Western China ( zh, s=中国西部, l=, labels=no or zh, s=华西, l=, labels=no) is the west of China. It consists of Southwestern China and Northwestern China. In the definition of the Chinese government, Western China covers six provinces ...
to teach
preventive medicine
Preventive healthcare, or prophylaxis, is the application of healthcare measures to prevent diseases.Hugh R. Leavell and E. Gurney Clark as "the science and art of preventing disease, prolonging life, and promoting physical and mental health a ...
in
missionary
A missionary is a member of a Religious denomination, religious group who is sent into an area in order to promote its faith or provide services to people, such as education, literacy, social justice, health care, and economic development.Thoma ...
hospitals. The family returned to the United Kingdom about a year after Parfit was born, settling in Oxford. Parfit was educated at the
Dragon School and
Eton College
Eton College ( ) is a Public school (United Kingdom), public school providing boarding school, boarding education for boys aged 13–18, in the small town of Eton, Berkshire, Eton, in Berkshire, in the United Kingdom. It has educated Prime Mini ...
, where he was nearly always at the top of the regular rankings in every subject except maths. From an early age, he endeavoured to become a poet, but he gave up
poetry
Poetry (from the Greek language, Greek word ''poiesis'', "making") is a form of literature, literary art that uses aesthetics, aesthetic and often rhythmic qualities of language to evoke meaning (linguistics), meanings in addition to, or in ...
towards the end of his adolescence.
He then studied modern history at
Balliol College, Oxford
Balliol College () is a constituent college of the University of Oxford. Founded in 1263 by nobleman John I de Balliol, it has a claim to be the oldest college in Oxford and the English-speaking world.
With a governing body of a master and aro ...
, graduating in 1964. In 1965–66, he was a
Harkness Fellow
The Harkness Fellowship (previously known as the Commonwealth Fund Fellowship) is a program run by the Commonwealth Fund of New York City. This fellowship was established to reciprocate the Rhodes Scholarships and enable Fellows from several cou ...
at
Columbia University
Columbia University in the City of New York, commonly referred to as Columbia University, is a Private university, private Ivy League research university in New York City. Established in 1754 as King's College on the grounds of Trinity Churc ...
and
Harvard University
Harvard University is a Private university, private Ivy League research university in Cambridge, Massachusetts, United States. Founded in 1636 and named for its first benefactor, the History of the Puritans in North America, Puritan clergyma ...
. He abandoned historical studies for philosophy during the fellowship.
Career
Parfit returned to Oxford to become a fellow of
All Souls College
All Souls College (official name: The College of All Souls of the Faithful Departed, of Oxford) is a constituent college of the University of Oxford in England. Unique to All Souls, all of its members automatically become fellows (i.e., full me ...
. He held this position until age 67, at which point the university's policy mandates retirement. He remained a regular visiting professor at Harvard, New York University, and Rutgers.
Ethics and rationality
''Reasons and Persons''
In ''Reasons and Persons'', Parfit suggested that nonreligious ethics is a young and fertile field of inquiry. He asked questions about which actions are right or wrong and shied away from
meta-ethics
In metaphilosophy and ethics, metaethics is the study of the nature, scope, ground, and meaning of moral judgment, ethical belief, or values. It is one of the three branches of ethics generally studied by philosophers, the others being normativ ...
, which focuses more on
logic
Logic is the study of correct reasoning. It includes both formal and informal logic. Formal logic is the study of deductively valid inferences or logical truths. It examines how conclusions follow from premises based on the structure o ...
and language.
In Part I of ''Reasons and Persons'' Parfit discussed self-defeating moral theories, namely the
self-interest theory of rationality ("S") and two ethical frameworks: common-sense morality and
consequentialism
In moral philosophy, consequentialism is a class of normative, teleological ethical theories that holds that the consequences of one's conduct are the ultimate basis for judgement about the rightness or wrongness of that conduct. Thus, from a ...
. He posited that self-interest has been dominant in Western culture for over two millennia, often making bedfellows with religious doctrine, which united self-interest and morality. Because self-interest demands that we always make self-interest our supreme rational concern and instructs us to ensure that our whole life goes as well as possible, self-interest makes temporally neutral requirements. Thus it would be irrational to act in ways that we know we would prefer later to undo.
As an example, it would be irrational for fourteen-year-olds to listen to loud music or get arrested for vandalism if they knew such actions would detract significantly from their future well-being and goals (such as having good hearing, a good job, or an academic career in philosophy).
Most notably, the self-interest theory holds that it is irrational to commit any acts of self-denial or to act on desires that negatively affect our well-being. One may consider an aspiring author whose strongest desire is to write a masterpiece, but who, in doing so, suffers depression and lack of sleep. Parfit argues that it is plausible that we have such desires which conflict with our own well-being, and that it is not necessarily irrational to act to fulfill these desires.
Aside from the initial appeal to plausibility of desires that do not directly contribute to one's life going well, Parfit contrived situations where self-interest is indirectly self-defeating—that is, it makes demands that it initially posits as irrational. It does not fail on its own terms, but it does recommend adoption of an alternative framework of rationality. For instance, it might be in my self-interest to become trustworthy to participate in mutually beneficial agreements, even though in maintaining the agreement I will be doing what will, other things being equal, be worse for me. In many cases self-interest instructs us precisely not to follow self-interest, thus fitting the definition of an indirectly self-defeating theory.
Parfit contended that to be indirectly individually self-defeating and directly collectively self-defeating is not fatally damaging for S. To further bury self-interest, he exploited its partial relativity, juxtaposing temporally neutral demands against agent-centred demands. The appeal to full relativity raises the question whether a theory can be consistently neutral in one sphere of actualisation but entirely partial in another. Stripped of its commonly accepted shrouds of plausibility that can be shown to be inconsistent, self-interest can be judged on its own merits. While Parfit did not offer an argument to dismiss S outright, his exposition lays self-interest bare and allows its own failings to show through. It is defensible, but the defender must bite so many bullets that they might lose their credibility in the process. Thus a new theory of rationality is necessary. Parfit offered the "critical present aim theory", a broad catch-all that can be formulated to accommodate any competing theory. He constructed critical present aim to exclude self-interest as our overriding rational concern and to allow the time of action to become critically important. But he left open whether it should include "to avoid acting wrongly" as our highest concern. Such an inclusion would pave the way for ethics.
Henry Sidgwick
Henry Sidgwick (; 31 May 1838 – 28 August 1900) was an English Utilitarianism, utilitarian philosopher and economist and is best known in philosophy for his utilitarian treatise ''The Methods of Ethics''. His work in economics has also had a ...
longed for the fusion of ethics and rationality, and while Parfit admitted that many would avoid acting irrationally more ardently than acting immorally, he could not construct an argument that adequately united the two.
Where self-interest puts too much emphasis on the separateness of persons, consequentialism fails to recognise the importance of bonds and emotional responses that come from allowing some people privileged positions in one's life. If we were all pure do-gooders, perhaps following Sidgwick, that would not constitute the outcome that would maximise happiness. It would be better if a small percentage of the population were pure do-gooders, but others acted out of love, etc. Thus consequentialism too makes demands of agents that it initially deemed immoral; it fails not on its own terms, for it still demands the outcome that maximises total happiness, but does demand that each agent not always act as an impartial happiness promoter. Consequentialism thus needs to be revised as well.
Self-interest and consequentialism fail indirectly, while common-sense morality is directly collectively self-defeating. (So is self-interest, but self-interest is an ''individual'' theory.) Parfit showed, using interesting examples and borrowing from Nashian games, that it would often be better for us all if we did not put the welfare of our loved ones before all else. For example, we should care not only about our kids, but everyone's kids.
''On What Matters''
In his second book, Parfit argues for
moral realism
Moral realism (also ethical realism) is the position that ethical sentences express propositions that refer to objective features of the world (that is, features independent of subjective opinion), some of which may be true to the extent that t ...
, insisting that moral questions have true and false answers. Further, he suggests that three categories of ethical theory—
Kantian
Kantianism () is the philosophy of Immanuel Kant, a German philosopher born in Königsberg, Prussia (now Kaliningrad, Russia). The term ''Kantianism'' or ''Kantian'' is sometimes also used to describe contemporary positions in philosophy of mi ...
deontology
In moral philosophy, deontological ethics or deontology (from Greek language, Greek: and ) is the normative ethics, normative ethical theory that the morality of an action should be based on whether that action itself is right or wrong under a ...
,
consequentalism, and
contractualism
Contractualism is a term in philosophy which refers either to a family of political theories in the social contract tradition (when used in this sense, the term is an umbrella term for all social contract theories that include contractarianism), ...
—converge on the same answers to moral questions.
In the conclusion of the third volume, published shortly after his death, Parfit writes that the affluent have strong moral obligations to the poor:
One thing that greatly matters is the failure of we rich people to prevent, as we so easily could, much of the suffering and many of the early deaths of the poorest people in the world. The money that we spend on an evening’s entertainment might instead save some poor person from death, blindness, or chronic and severe pain. If we believe that, in our treatment of these poorest people, we are not acting wrongly, we are like those who believed that they were justified in having slaves.
Some of us ask how much of our wealth we rich people ought to give to these poorest people. But that question wrongly assumes that our wealth is ours to give. This wealth is legally ours. But these poorest people have much stronger moral claims to some of this wealth. We ought to transfer to these people ..at least ten per cent of what we earn.
He also concludes that responding to risks to humanity's survival is what "matters most", with humanity's descendants or successors having the potential to spread through the galaxy and create unprecedented good over billions of years.
Criticism
In his book ''On Human Nature'',
Roger Scruton
Sir Roger Vernon Scruton, (; 27 February 194412 January 2020) was an English philosopher, writer, and social critic who specialised in aesthetics and political philosophy, particularly in the furtherance of Conservatism in the United Kingdom, c ...
criticised Parfit's use of moral dilemmas such as the
trolley problem
The trolley problem is a series of thought experiments in ethics, psychology, and artificial intelligence involving stylized ethical dilemmas of whether to sacrifice one person to save a larger number. The series usually begins with a Scenario ...
and
lifeboat ethics to support his ethical views, writing, "These 'dilemmas' have the useful character of eliminating from the situation just about every morally relevant relationship and reducing the problem to one of arithmetic alone." Scruton believed that many of them are deceptive; for example, he does not believe one must be a consequentialist to believe that it is morally required to pull the switch in the trolley problem, as Parfit assumes. He instead suggests that more complex dilemmas, such as
Anna Karenina's choice to leave her husband and child for Vronsky, are needed to fully express the differences between opposing ethical theories, and suggests that deontology is free of the problems that (in Scruton's view) beset Parfit's theory.
Personal identity
Parfit was singular in his meticulously rigorous and almost mathematical investigations into personal identity. In some cases, he used examples seemingly inspired by ''
Star Trek
''Star Trek'' is an American science fiction media franchise created by Gene Roddenberry, which began with the Star Trek: The Original Series, series of the same name and became a worldwide Popular culture, pop-culture Cultural influence of ...
'' and other science fiction, such as the
teletransporter, to explore our intuitions about our identity. He was a
reductionist, believing that since there is no adequate criterion of personal identity, people do not exist apart from their components. Parfit argued that reality can be fully described impersonally: there need not be a determinate answer to the question "Will I continue to exist?" We could know all the facts about a person's continued existence and not be able to say whether the person has survived. He concluded that we are mistaken in assuming that personal identity is what matters in survival; what matters is rather "Relation R": psychological connectedness (namely, of memory and character) and continuity (overlapping chains of strong connectedness).
Following
David Hume
David Hume (; born David Home; – 25 August 1776) was a Scottish philosopher, historian, economist, and essayist who was best known for his highly influential system of empiricism, philosophical scepticism and metaphysical naturalism. Beg ...
, Parfit argued that no unique entity, such as a self, unifies a person's experiences and dispositions over time. Therefore personal identity is not "what matters" in survival.
A key Parfitian question is: given the choice between surviving without psychological continuity and connectedness (Relation R) and dying but preserving R through someone else's future existence, which would you choose? Parfit argues the latter is preferable.
Parfit described his loss of belief in a separate self as liberating:
Criticism of personal identity view
Fellow reductionist
Mark Johnston of Princeton rejects Parfit's constitutive notion of identity with what he calls an "Argument from Above". Johnston maintains, "Even if the lower-level facts
hat make up identitydo not in themselves matter, the higher-level fact may matter. If it does, the lower-level facts will have derived significance. They will matter, not in themselves, but because they constitute the higher level fact."
In this, Johnston moves to preserve the significance of personhood. Parfit's explanation is that it is not personhood itself that matters, but rather the facts in which personhood consists that provide it with significance. To illustrate this difference between himself and Johnston, Parfit used an illustration of a brain-damaged patient who becomes irreversibly unconscious. The patient is certainly still alive even though that fact is separate from the fact that his heart is still beating and other organs are still functioning. But the fact that the patient is alive is not an independent or separately obtaining fact. The patient's being alive, even though irreversibly unconscious, simply consists in the other facts. Parfit explains that from this so-called "Argument from Below" we can arbitrate the value of the heart and other organs still working without having to assign them derived significance, as Johnston's perspective would dictate.
Population ethics and future generations
Non-identity problem
The
non-identity problem arises from the observation that actions taken today can fundamentally alter which future people come into existence. In chapter 16 of ''Reasons and Persons'', Parfit posits that one's existence is intimately related to the time and conditions of one's conception.
He calls this "The Time-Dependence Claim": "If any particular person had not been conceived when he was in fact conceived, it is in fact true that he would never have existed".
Like the
butterfly effect
In chaos theory, the butterfly effect is the sensitive dependence on initial conditions in which a small change in one state of a deterministic nonlinear system can result in large differences in a later state.
The term is closely associated w ...
in
chaos theory
Chaos theory is an interdisciplinary area of Scientific method, scientific study and branch of mathematics. It focuses on underlying patterns and Deterministic system, deterministic Scientific law, laws of dynamical systems that are highly sens ...
, small changes in initial conditions can have profound downstream effects on human reproduction. Actions may not just affect the welfare of future individuals, but also cause different individuals to be born. If the moral ramifications of potential policies are considered in
person-affecting terms, there is no reason to prefer a sound policy over an unsound one, provided that its effects are not felt by the next few generations.
Parfit eventually became convinced that personal identity is irrelevant to ethics.
He wrote about an article in ''
The Times
''The Times'' is a British Newspaper#Daily, daily Newspaper#National, national newspaper based in London. It began in 1785 under the title ''The Daily Universal Register'', adopting its modern name on 1 January 1788. ''The Times'' and its si ...
'' in which a politician praised a recent decline in teenage pregnancy. A man wrote a letter saying he had had a teenage mother and, although the early years had been hard, he now had a life thoroughly worth living. The man asked whether the politician was suggesting it would have been better if he had never been born. Parfit said the man would waive the right to have such-and-such level of a good start in life merely to exist. He wrote, "The objection must be that if she had waited, she could have given to some other child a better start in life."
Mere addition paradox and repugnant conclusion
In part four of ''Reasons and Persons'', Parfit discusses possible futures for the world.
He discusses possible futures and population growth in chapter 17, and argues that both
average and total utilitarianism result in unwelcome conclusions when applied to population.
In the section titled "Overpopulation", Parfit distinguishes between average utilitarianism and total utilitarianism. He formulates average utilitarianism in two ways. One is what Parfit calls the "Impersonal Average Principle", which he formulates as "If other things are equal, the best outcome is the one in which people's lives go, on average, best."
The other is what he calls the "Hedonistic version"; he formulates this as "If other things are equal, the best outcome is the one in which there is the greatest average net sum of happiness, per life lived."
Parfit then gives two formulations of the total utilitarianism view. The first formulation Parfit calls the "Hedonistic version of the Impersonal Total Principle": "If other things are equal, the best outcome is the one in which there would be the greatest quantity of happiness—the greatest net sum of happiness minus misery."
He then describes the other formulation, the "non-Hedonistic Impersonal Total Principle": "If other things are equal, the best outcome is the one in which there would be the greatest quantity of whatever makes life worth living."

Applying total utilitarian standards (absolute total happiness) to possible population growth and welfare leads to what he calls the
repugnant conclusion: "For any possible population of at least ten billion people, all with a very high quality of life, there must be some much larger imaginable population whose existence, if other things are equal, would be better, even though its members have lives that are barely worth living."
Parfit illustrates this with a simple thought experiment: imagine a choice between two possible futures. In A, 10 billion people would live during the next generation, all with extremely happy lives, lives far happier than anyone's today. In B, there are 20 billion people all living lives that, while slightly less happy than those in A, are still very happy. Under total utility maximisation we should prefer B to A. Therefore, through a regressive process of population increases and happiness decreases (in each pair of cases the happiness decrease is outweighed by the population increase) we are forced to prefer Z, a world of hundreds of billions of people all living lives barely worth living, to A. Even if we do not hold that coming to exist can benefit someone, we still must at least admit that Z is no worse than A.
Parfit and other philosophers have explored a number of potential ways to avoid this "repugnant conclusion", many of which are discussed in ''Reasons and Persons''. Parfit himself spent significant time trying to find a coherent ethical theory that would avoid it.
One potential objection challenges what life in the A-world would be like and whether life in the Z-world would differ very much from a normal privileged life. Another one proposes that movement from the A-world to the Z-world can be blocked by discontinuity.
Negative utilitarians may reject the premise of maximizing happiness, emphasizing the converse, the minimization of suffering.
Philosopher
Larry Temkin challenges the assumption that the "better than" relation is
transitive. Others proposed a minimal threshold of liberties and primary social goods to be distributed, or suggested to adopt a
deontological
In moral philosophy, deontological ethics or deontology (from Greek language, Greek: and ) is the normative ethics, normative ethical theory that the morality of an action should be based on whether that action itself is right or wrong under a ...
approach that looks to values and their transmission through time.
[Various authors of essays in ''The Repugnant Conclusion,'' eds. Jesper Ryberg and Torbjörn Tännsjö (]Kluwer Academic Publishers
Springer Science+Business Media, commonly known as Springer, is a German multinational publishing company of books, e-books and peer-reviewed journals in science, humanities, technical and medical (STM) publishing.
Originally founded in 1842 in ...
, 2004) ; and, Young Kim
Justice as Right Actions: An Original Theory of Justice in Conversation with Major Contemporary Accounts
(Lexington Books
Bloomsbury Publishing plc is a British worldwide publishing house of fiction and non-fiction. Bloomsbury's head office is located on Bedford Square in Bloomsbury, an area of the London Borough of Camden. It has a US publishing office located in ...
, 2015) ch.10 ( ). Michael Huemer and
Torbjörn Tännsjö endorse the conclusion, considering that the repugnance comes from intuitions that should be revised. In 2021, a number of philosophers said that avoiding the repugnant conclusion was receiving excessive focus and should not be considered a necessary condition for an adequate theory of
population ethics
Population ethics is the philosophical study of the ethical problems arising when our actions affect ''who'' is born and ''how many'' people are born in the future. An important area within population ethics is population axiology, which is "the s ...
.
Against average utilitarianism, Parfit also argues that if all that matters is average happiness, then the best population could be arbitrarily small, for example containing only a few extremely happy individuals. Moreover, this would imply that adding people with lives worth living would make the world worse if these are less happy than the average.
Personal life
Parfit met
Janet Radcliffe Richards in 1982,
and they then began a relationship that lasted until his death.
They married in 2010.
Richards believes Parfit had
Asperger syndrome
Asperger syndrome (AS), also known as Asperger's syndrome or Asperger's, is a diagnostic label that has historically been used to describe a neurodevelopmental disorder characterized by significant difficulties in social interaction and no ...
.
Parfit supported
effective altruism
Effective altruism (EA) is a 21st-century philosophical and social movement that advocates impartially calculating benefits and prioritizing causes to provide the greatest good. It is motivated by "using evidence and reason to figure out how to b ...
.
He was a member of
Giving What We Can and pledged to donate at least 10% of his income to effective charities.
Parfit was an avid photographer who regularly traveled to
Venice
Venice ( ; ; , formerly ) is a city in northeastern Italy and the capital of the Veneto Regions of Italy, region. It is built on a group of 118 islands that are separated by expanses of open water and by canals; portions of the city are li ...
and
St. Petersburg to photograph architecture.
Selected works
*1964: ''Eton Microcosm''. Edited by Anthony Cheetham and Derek Parfit. London: Sidgwick & Jackson.
*1971: "Personal Identity". ''Philosophical Review''. vol. 80: 3–27.
*1979: "Is Common-Sense Morality Self-Defeating?". ''The Journal of Philosophy'', vol. 76, pp. 533–545, October.
*1984: ''
Reasons and Persons
''Reasons and Persons'' is a 1984 book by the philosopher Derek Parfit, in which the author discusses ethics, rationality and personal identity.
It is divided into four parts, dedicated to self-defeating theories, rationality and time, personal ...
''. Oxford: Clarendon Press.
*1992: "Against the social discount rate" (with
Tyler Cowen
Tyler Cowen (; born January 21, 1962) is an American economist, columnist, blogger, and podcaster. He is a professor at George Mason University, where he holds the Holbert L. Harris chair in the economics department.
Cowen writes the "Economic ...
), in Peter Laslett & James S. Fishkin (eds.) ''Justice between age groups and generations'', New Haven: Yale University Press, pp. 144–161.
*1997: "Reasons and Motivation". ''The Aristotelian Soc. Supp.'', vol. 77: 99–130.
*2003:
*2006: "Normativity", in Russ Shafer-Landau (ed.). ''Oxford Studies in Metaethics'', vol. I. Oxford: Clarendon Press.
*2011: ''
On What Matters'', vols. 1 and 2. Oxford University Press.
*2017: ''
On What Matters'', vol. 3. Oxford University Press.
References
Further reading
* David Edmonds, ''Parfit: A Philosopher and his Mission to Save Morality'' (Princeton, Princeton University Press, 2023).
*
* Jussi Suikkanen and John Cottingham (Editors), ''Essays on Derek Parfit's'' On What Matters (Oxford, Wiley-Blackwell, 2009).
{{DEFAULTSORT:Parfit, Derek
1942 births
2017 deaths
20th-century English philosophers
21st-century English philosophers
Alumni of Balliol College, Oxford
Analytic philosophers
British ethicists
Columbia University alumni
Fellows of All Souls College, Oxford
Harkness Fellows
Harvard University staff
Harvard University Department of Philosophy faculty
Moral realists
New York University faculty
People associated with effective altruism
People educated at Eton College
Philosophers of identity
Rolf Schock Prize laureates
Fellows of the British Academy