Derek Parfit

Derek Antony Parfit (11 December 1942 – 2 January 2017) was a British philosopher who specialised in personal identity, rationality, and ethics.

He is widely considered one of the most important and influential moral philosophers of the late 20th and early 21st centuries.

Parfit was born in 1942 in Chengdu, China, the son of Jessie (née Browne) and Norman Parfit, medical doctors who had moved to Western China to teach preventive medicine in missionary 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, 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 towards the end of his adolescence.

He then studied Modern History at Balliol College, Oxford, graduating in 1964.

In 1965–66, he was a Harkness Fellow at Columbia University and Harvard University.

He abandoned historical studies for philosophy during the fellowship.

Parfit returned to Oxford to become a fellow of All Souls College, where he remained until he was 67, when the university’s mandatory retirement policy required him to leave both the college and the faculty of philosophy.

He retained his appointments as regular Visiting Professor at Harvard, NYU, and Rutgers until his death.

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, which focuses more on logic 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.

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.

Parfit rose to prominence in 1971 with the publication of his first paper, "Personal Identity".

His first book, Reasons and Persons (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, where he was an Emeritus Senior Research Fellow at All Souls College at the time of his death.

He was also a visiting professor of philosophy at Harvard University, New York University, and Rutgers University.

He was awarded the 2014 Rolf Schock Prize "for his groundbreaking contributions concerning personal identity, regard for future generations, and analysis of the structure of moral theories."