Derek Parfit (born December 11, 1942) is a
British philosopher who specializes in problems of
personal identity, rationality and
ethics, and the relations between them. His 1984 book,
Reasons and Persons (described by Alan
Ryan in The Sunday Times as "something close to a
work of genius") has been very influential in the field. He is a Senior Research Fellow at All Souls College, Oxford and a Visiting Professor of Philosophy at New York University, Harvard University, and
Rutgers University.
Ethics and rationality
Reasons and Persons is a four-part work, each successive section building on the last. Parfit believes that
non-religious ethics is a young and fertile field of inquiry. In many ways, he serves as a foil to Wittgenstein, directing his study inwards to address the everyday mechanics of moral problems. He
asks questions about which actions are right or wrong, and shies away from meta-ethics which
focuses more on logic and language.
In Part I of Reasons and Persons Parfit discusses "self-defeating theories", namely the self
interest theory of rationality (S) and two ethical frameworks: common sense morality (CSM) and consequentialism (C). He posited that the S has been dominant in Western culture for over two
millennia, often making bedfellows with religious doctrine, which united self interest and morality. Because S 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, S
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 is irrational for my 14-year-old self to listen to loud music and get arrested for vandalism if I know such
actions would detract significantly from my future well-being and goals (such as an academic career in philosophy).
Most notably, the self-interest theory holds that it is irrational to make 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 an award-winning novel.
However, in doing so, she suffers due to lack of sleep and depression. Parfit holds that it is plausible that we have such
desires outside our own well-being, and that it is not 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
contrives situations where S 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 own self interest to become trustworthy in order to participate in mutually beneficial agreements, despite the fact that
in maintaining the agreement I will be doing, ceteris paribus, what will be worse for
me. In many cases S instructs us precisely not to follow S, thus fitting the definition of an indirectly self-defeating
theory.
Parfit contends that to be indirectly individually self-defeating and directly collectively self defeating is not fatally
damaging for S. To further bury S, Parfit exploits its partial relativity, juxtaposing temporally neutral demands against agent
centered demands. The appeal to full relativity raises the question whether a theory can be consistently neutral in one sphere of
actualization but entirely partial in another. Stripped of its commonly accepted shrouds of plausibility that can be shown to be
inconsistent, S can be judged on its own (lacking) merits. While Parfit cannot offer an argument to dismiss S outright, his
exposition lays S bare and allows its own failings to show through. It is defensible but the defender must bite so many bullets
that he might lose his credibility in the process. This is clearly undesirable thus we need to search for a new theory of
rationality. Parfit offers the Critical Present Aim Theory (CP), a broad catch-all that can be formulated to accommodate any
competing theory. Parfit constructs CP to exclude self interest as our over-riding rational concern and to allow the time of
action to become critically important. He leaves the question open, however, whether it should include "to avoid acting wrongly"
as our highest concern. Such an inclusion would pave the way for ethics. Henry Sidgwick
longed for the fusion of ethics and rationality and, while Parfit admits that many would more ardently avoid acting irrationally
as opposed to immorally, he cannot construct an argument that adequately unites the two.
S is not the only self-defeating theory however. Where S puts too much emphasis on the separateness of persons, C fails to
recognize the importance of bonds and emotional responses that comes 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 maximize
happiness. It would be better if a small percentage of the population were pure do-gooders, but others acted out of love, etc.
Thus C too makes demands of agents that it initially deemed immoral; it fails not on its own terms, for it still demands the
outcome that maximizes total happiness, but does demand that each agent not always act as impartial happiness promoters. C thus
needs to be revised as well.
S and C fail indirectly, while CSM is directly collectively self-defeating. (So is S but S is an individual theory.)
Parfit shows, 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.
Parfit often poses more questions than he answers. In ethics, he points to a need for a dynamic framework that combines CSM
and C but does not offer any specific solution. Such an attitude tracks his stance that non-Religious ethics is a young, fertile
field.
Self identity
Parfit uses many examples seemingly inspired by Star Trek and other science fiction, such as the teletransporter, to explore emotions
and feelings regarding self-identity. He is a reductionist, believing that self-identity
can be reduced to a set of criteria that need not suppose that people do exist. To Parfit, Identity can be fully described
impersonally: there need not be a determinate answer to the question "Will the person that continues to exist remain to be me?"
We could know all the facts about an entity's continued existence and not be able to answer the question of whether or not the
persisting person possesses a continual identity. He concludes that we are mistaken in assuming that personal identity is what
matters, but rather that Relation R does: psychological connectedness (namely, of memory and character) and continuity
(overlapping chains of strong connectedness).
In Parfit's system, individuals are nothing more than our brains and our bodies, but identity cannot be reduced to either, for
identity, in the classical sense, is not what matters. Rather, Relation R is the point around which Parfit's theories turn.
Parfit concedes that his theories rarely conflict with rival Reductionist theories in everyday life, and are only brought to
blows by the introduction of extraordinary examples. However, he defends their usage in that they seem to arouse genuine and
strong feelings in many of us. Identity is not as determinate as we often suppose it is, but instead, such determinacy owes
itself mainly to the way we talk. People exist in the same way that nations or clubs exist (which may be raised as support for
the existence of corporations and corporate law).
A key Parfitian question is: given the choice to maintain your personal identity or your psychological continuity, which would
you choose? Would one prefer to die (a loss of character but a persistence of personal identity), or instead have one's personal
identity fragmented, but retain one's personality?
The future
Parfit's most famous postulations come in Part IV of Reasons and Persons where he discusses possible futures for the
world. He shows that, in the discussion of possible futures, both average and total utilitarian standards lead to unwelcome
conclusions. Applying total utilitarian standards (absolute total happiness) to possible growth paths of population and welfare
leads one to what he calls the Repugnant Conclusion. Parfit illustrates this with
a simple thought experiment. Imagine a choice between possible futures, in A 10 billion people would live during the next
generation all having extremely happy lives, lives far happier than anyone lives today. In B, there are 20 billion people all
living lives, while slightly less happy than those in A, are still very happy. Under total utility maximization we would prefer B
to A, and through a regressive process of population increases and happiness decreases (in each the happiness decrease is more
than outweighed by the population increase) we are forced to prefer Z, a world of 100's of billion people all living lives barely
worth living, over 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 makes a similar argument against average utilitarian standards. If all we care about is average happiness, we would be
forced to conclude that an extremely small population, say 10 people, over the course of human history is the best outcome if we
assume that these first 10 people (Adam and Eve et al.) had lives happier than we could ever imagine. Then consider the case of
American immigration. Presumably alien welfare is less than American, but the would-be alien benefits tremendously from moving
from his homeland. Assume also that Americans benefit from immigration (at least in small doses) because they get cheap labor,
etc. Under immigration both groups are better off, but if this increase is offset by increase in the population, then average
welfare is lower. Thus although everyone is better off, this is not the preferred outcome. Parfit asserts that this is simply
absurd.
Parfit then moves to discuss the identity of future generations. He first posits that one's existence is intimately related to
the time and conditions of conception. I would not be me if my parents waited 2 more years to have a child. While they would
still have had a child, it would certainly be another being; even if it were still their first born son, it would not be me.
Study of weather patterns and other physical phenomena in the 20th century has shown
that very minor changes in the initial conditions at time T, have drastic effects at all points after T. Compare this to the
romantic involvement of future childbearing partners. By this we can see that any actions taken today, at time T, will affect the
resulting people that exist after only a few generations. For instance, a significant change in global environmental policy would
shift the initial conditions of the conception process so much that after 300 years none of the same people that would have been
born are in fact born. Different couples meet each other and conceive at different times -- different people exist. This is known
as the 'non-identity problem.'
We could therefore craft disastrous policies that would be worse for nobody, because none of the same people exist under the
different policies. If we consider the moral ramifications of potential policies in person-affecting terms, then we will have no
reason to prefer a sound policy over an unsound one provided that its effects are not felt for a few generations. This is the
non-identity crisis in its purest form: the identity of future generations is causally dependent, in a very sensitive way, on the
actions the present generations. So much so that they effectively have no identity if one looks as little as a half century into
the future. Philosophers have long ignored this problem and have devised systems of ethics that are powerless to argue against
our temporally biased policies.
Works by Parfit
- Reasons and Persons, Oxford University Press, 1984.
- "Reasons and Motivation"", The Aristotelian Soc. Supp. Vol. 77: 99-130, 1997.
- "Normativity", in Russ Shafer-Landau (ed.), Oxford Studies in Metaethics, vol. I, Clarendon, Oxford, 2006.
- Climbing the Mountain, forthcoming. A 310 page unpublished manuscript that Parfit has been working on for at
least 15 years and which has been widely circulated throughout the professional philosophical community.
External links
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