In this essay I will examine
Parfit’s non-identity problem (NIP) and its relevance in modern political
discourse on trans-generational justice. Firstly, I will detail Parfit’s own
thoughts on the matter. Following this, I shall criticise Parfit’s conclusions
with reference to James Woodward and Rahul Kumar in particular, and argue that
we can overcome the NIP, though not for the reasons Parfit suggests.
The NIP suggests that decisions we make with the intention
of benefitting future generations instead harms future generations. Parfit
(1984) explains the NIP with the example of a 14 year-old girl. In this
example, a 14 year old girl decides to have a child, and is told that by having
the child now she is giving the child a worse start in life than if she waits
to have the child when she is older and more capable of looking after it. The
NIP suggests that we cannot claim that by delaying the pregnancy the girl in
question is improving the life of the child. This is because the child she
would have at 14 and the child she would have if she waited are not the same
person. It will be a different egg and a different sperm that create the two
children. We cannot say that by waiting until she is older the girl ensures a
better life for the child she was going to have at 14. Rather, that by waiting,
she causes the child not to exist. Parfit summaries this neatly when he says,
“We cannot claim that this girl's decision (to have the child at 14) was worse
for her child… in the different outcomes, different people would be born”
(Parfit, 1984, p. 359). When faced with the options of not existing versus a
worse start in life we cannot say that the girl has made the worse decision for
her child by choosing the latter (by having the child at 14 rather than
waiting). In short the NIP is the suggestion that, when making decisions
designed to benefit future generations, we are causing those we intended to
benefit not to exist and thus are harming them rather than helping them.
Parfit (1984) illustrates the relevance of the NIP with his
principle of depletion vs principle of conservation example. Society must
choose between two principles. This choice is one between the principles of
depletion, where we use up all the fossil fuels and have a high quality of life
but once the fuel runs out (after 200 years) the quality of life drops
considerably, or the principle of conservation, where we ensure the
preservation of fossil fuels so that they are available for longer in the
future. As a result, the quality of life remains consistently good for longer
under the principle of conservation, though marginally lower than during the
initial two-hundred years or so under the principle of depletion. The principle
of conservation ensures that the quality of life remains consistently good
after the 200 year mark whereas the principle of depletion ensures that after
the 200 year mark the quality of life falls disproportionately. The obvious
choice here seems to be the principle of conservation because millions of
people would be better off in the future, whereas under the principle of
depletion millions will live poor lives in the future once the fuel runs out.
This view is challenged by the NIP. If we choose the principle
of conservation our decision will completely alter the lives of the people in
the present and as such they would find different times to procreate than they
would under depletion, which would mean two different generations under the
principle of depletion and the principle of conservation (Parfit, 1984). For
example, if we choose the principle of conservation then Joe must walk home
instead of drive, he gets home 30 minutes later than he would under depletion.
As a result he procreates with his wife 30 minutes later than he would have
under depletion. This creates a completely different child from the one who
would have lived under depletion. The choice of the principle of conservation
results in the non-existence of many, who, under the principle of depletion,
would have existed and benefitted from the higher, though shorter-term, quality
It is true that the principle
of depletion would mean a hard life for millions of people but “since it would
be different people who would later live, these policies would not be worse for
any of these people” (Parfit, 2011, p. 218). Thus understood, in our attempts
to benefit future generations we are actually harming them by causing them not
to exist at all.
Parfit’s (1984) solution to the NIP is the “no difference
view”. He argues that regardless of who lives in the future it’s not desirable
to create a world in which they have worse lives than they could have, moreover
if we have the opportunity to enhance others’ lives we should do so. The no
difference view is that it does not matter who lives in the future, what
matters is that the actions we take in the present do effect whomever may come
to be in the future (Parfit, 2011).
means that matters of justice across generations are not affected by the NIP.
That is, it is irrelevant who eventually is born, we must strive to give them a
good life. Parfit introduces the idea of a general person, who, he explains,
“is a large group of possible people, one of whom will be actual.” (Parfit,
2011, p. 220) In the example of the 14 year old girl the child in question is a
“general person”. Under the no difference view we have a simple choice which is
to let that “general” child become a real person with a compromised start or a
real person with a relatively uncompromised start. As a result we should advise
against early pregnancy. All we care about is the fact that a child will be
worse off if the girl gives birth at 14.
This logic applies to the principle of depletion vs
principle of conservation argument. The no difference view suggests that we
should conserve because we have a choice to create a society in which the
“general people” become real people who have good lives (conserve) or poor
lives (depletion). We do not favour a world in which they have worse lives than
they could have. Instead we recognise that we have the opportunity to improve
the lives of future generations by choosing the principle of conservation.
However, I do not believe that the no difference view overcomes the NIP because
it works within the consequentialist parameters established by the NIP.
The NIP considers justice to be consequential in nature.
That is, I have acted unjustly if my action ends with someone being harmed in
some way. I shall argue that this is the wrong way to think about justice.
Instead, I believe that the act of doing something unjust is enough for said
act to be labelled unjust regardless of whether the outcome you produce is
better or worse for whomever you have acted against. As noted, Parfit’s no
difference view works within the consequentialist parameters and, as a result,
I find it unconvincing because it fails to properly consider more deontological
views of justice.
James Woodward (1986) criticises the consequentialist
thinking behind the NIP. Instead he champions two specific lines of thought.
The first concerns a deontological approach to justice, in which he argues that
actions are just as important as the final state of affairs when we talk about
issues of justice. It is not always acceptable to say that because we achieved
a positive end state we have acted justly. The second concerns particularism,
in that people have specific interests and it is not acceptable to override
these interests in order to pursue a more common good.
Woodward’s (1986) airliner example is a good illustration of
the failings of consequentialism in the NIP. Imagine you try to board a plane
but the airliner refuses you entry due to your ethnicity. You later find out
that the plane you wanted to board crashed and all the passengers died. Despite
the fact that the airliners racist action has saved your life, the airliner has
still acted unjustly. Woodward argues this is because the airliner has
infringed on your basic expectations about rights (specifically the right not
to be discriminated against based on one’s ethnicity). An action that does so
is unjust regardless of the outcome.
In choosing the principle of depletion, the rights of those
who will live 200 years later are being infringed. We have a right to an
existence in which we have access to key resources like fossil fuels. I agree
with Woodward that the infringing of this right is not overruled by the
argument that they are actually better off under the principle of depletion
because they exist. In the same way as the discriminatory airline employee
acted unjustly towards the would-be passenger, despite saving their life, the
choice of the principle of depletion wrongs the future generations even if it
causes them to exist. When dealing with justice, the actions, not just the
consequences, must be considered. If the actions infringe on our rights then
they are not just, regardless of the outcome. The fact that the NIP ignores
this point and instead places too much emphasis on the consequentialist
features of justice represents a major flaw in the NIP’s logic.
Rahul Kumar presents similar objections. Kumar (2003, p.
111) argues that there are “types” of people who are entitled to expect things
of other “types” of people depending on the “type of situation”. A “type” of
person is not a real person; it is merely a set of characteristics that could
be applied to a person. The same is true of a “type of situation” in that it’s
a set of characteristics that can be applied to a specific situation. Kumar
gives the example of a student (James) who has an appointment with his teacher
(Peter). The teacher has made this commitment but is tired, and is trying to
think of a way in which it is permissible to go home. In this case the “type”
of person is a student and a teacher while the “type of situation” is an
interaction between a student and a teacher. The expectation here is what the
student can expect from the teacher rather than what James can expect from
We fit into a “type” if we have the relevant characteristics
of the type in question. This is important because, as Kumar (2003, p. 110)
suggests that what people can expect of each other is based on “both (a) what
expectations can in fact be defended on the basis of the relevant principle,
and (b) the relevant type descriptions that happen to fit her and her
circumstances at that time.” Wrongdoing is about violating the actions that can
be reasonably expected between the “types” of people involved. The consequences
are not as important as the NIP would suggest. For example, we can say that a
drunk driver has not met the simple expectation not to drive drunk and thus
wronged an individual if they drive near the individual. Even if the driver
does not hit the individual they have still wronged them because they have
failed to live up to what the individual could reasonably expect of them, to
not endanger other lives by drink driving.
The NIP suggests that one cannot complain of harm due to
poor decisions by previous generations as they exist as a result of the
decisions. Kumar (2003) suggests that one can complain of harm on the basis
that the previous generations did not do what could reasonably have been
expected of them. In the case of the 14 year-old girl, it is reasonable to
expect her to wait to ensure her child has a better life. If she has the child
at 14 the child could complain as her mother has not provided the sort of start
to life that could be reasonably expected from a mother “type” to a child
“type”. Furthermore, those born into the principle of depletion could argue
that they were wronged because previous generations did not provide a standard
of living that could be reasonably expected from the present people “type” to
the future people “type”. The NIP would suggest that neither the child nor the
‘principle of depletion generation’ could complain but I agree with Kumar that
the importance of failing to meet reasonable expectations would allow them to
complain. This is something that the NIP just does not consider and as a result
I believe Kumar’s argument nullifies the NIP.
To conclude, I believe that we can overcome Parfit’s NIP.
However, I do not believe Parfit’s solution, the no difference view, is valid
because it allows the NIP to describe justice as intrinsically
consequentialist. Instead I believe that an action can be unjust even if the
end result is positive. Consequently, I am sympathetic to Woodward’s argument,
which promotes a deontological view of justice, and Kumar’s argument that the
breaking of expectations is in itself wrong regardless of the consequences.
Both these critics highlight the consequentialist flaws of the NIP and prove
that we can overcome it by embracing a deontological view of justice. Kumar’s
deontological view successfully challenges the assertions of consequentialist
thinking that are prevalent in the NIP. Instead, Kumar’s argument for what we
can reasonably expect from past generations successfully challenges the NIP by
arguing that future generations would have legitimate reasons to complain if
previous generations had failed to do what can be reasonably expected from
them. He can therefore be seen to provide strong and compelling reasons to
choose the principle of conservation over the principle of depletion, in
overcoming the non-identity problem.
R. (2003) ‘Who can be wronged?’,
and Public Affairs,
31(2), pp. 99-118.
Parfit, D. (2011)
On What Matters.
Reasons and Persons.
J. (1986) ‘The Non-Identity Problem’,
96(4), pp. 804–831. Available at:
(Accessed: 10 December 2015).
© Jake Lehrle-Fry.
This article is licensed under a Creative Commons Attribution 4.0 International
Licence (CC BY).