Document 12364

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THER.E is another question about personal identity. Each of us might never
have eJ.isted. What would have made Ihis true? The answer produces a
problem that mosl of us overlook.
One of my aims in Part Four is to discuss this probltm. My other aim it
to discuss the part of our moral theory in which this problem ari&Cs. Thit is
the part that covers how we affect future generations. This is the most
important part of our moral theory, since the next few centuries will be the
most important in human history.
What would have made it true that some particular person would never
have uisted? With one qualification, I believe
The Time-Dependence Claim: Ir any particular person had not been
conceived when he was in flU:t conceived, it is ill fact true that he would
never have existed.
This claim is not obviously true. Thus one woman writes:
It iii always fascinating to sl'U'ulalc on who we would have been if our parentli had
married oilier people. I
In wondering who she would have been, tbis woman ignores the answer:
'No one'.
Though the Time-Dependence Claim is not ob\<busly true, it is not
controversial, and it is easy to believe. It is thus unlike the Reductionist
View about personal identity over time. This is one of severill competing
views, and is hard to believe. The Time-Dependence Claim is nOI about
personal identity over time. It is about a different though related subject:
penonaJ identity in different possible histories of tbe world. Several views
about this tubject are worth discussing. But the Time.Dependence Claim is
not Doe of the&e views. It is a claim that is true on all of these views.
AI I have said. the claim should be qualified. Each of us grew from a
perticular pair of cells: an ovum and the .permatozoon by which. out of
milliODa. it was fertiliu.d. Suppose that my melber bad not conceived a child
The Nem-ldentity Probkm
119. How Ow J."lity DeperuJs 0" When We Were C01Ice;\led
at the time when in fact she conceived me. And suppose that she: had
conceiVed a child within a few days of this time. This child would have grown
from the same particular ovum from which I grew. But even if this child had
been conceiVed only a few seconds earlier or later, it is almost certain that he:
would have grown from a different spermatozoon. This child would have had
some but not all of my senes. Would this child have been me?
We are: inclined to believe thai any question about our identity mwl have
an answer, which must be either Yes or No. As before, I rc:jc:ct. nus view.
There: are: cases in which our identity is indeterminate. What I have just
dCllCribed may be such a case. Ir it is, my question has no answer. It is
neiLbe:r true nor false thaI, if these events had occlJlTed, 1 would never have
e:xisted. Though J can always aak, 'Would I have al,tedr, this would here
be an empty question.
These last claims are: controvenial. Since I want my Time:-Dependence
Qaim not to be controversiaJ, I sbaJI set aside Lbese cases. The claim can
It is irrelevant that, because then:: can be twins, it is false that only Kanl
could have grown from this pair orcell8.
Holders or the Origin View would accept my claim that. if Kant had not
been conceived within a month of the: time when he was conceived. he
would in (acl never have existed. Ir he had not been conceived in that
month. no child would in fact have grown from the particular pair of cells
from which he grew. (1"lW; claim makes an II5Iwnption both about the
distinctive necessary properties of this pair of cells, and about the human
reproductive systml. But these assumptions are not controversial.)
According to certain other views, Kanl could have grown from a different
pair of cells. On
[TD2) Ir any particular person had not been conocived within
a month of the time: when he was in fact conceived, he would in
fBel never have existed.
I claim that this is itt fact true. I do not claim that it is necessarily true. The:
different views about tbis subject make competing claims about what is
necessary. It is because I claim less that my claim is not controversial. Those
who disagree about what could have happened may agree about what would
in fac, have happened. As I shall argue, the holde:rs of all plausible views
would agree with me.
1bese views make claims about the neceuary properties of each particular
person. Some ofa person's necessary properties are: had by eve:ryone:: these
are the properties that are: ncceuary lo being a penlOn. What concerns us
here: are: the distinctiJle necessary properties of each particular person.
Suppose I claim that P is one of Kant's distinctive necessary properties.
This means that Kant could not ha~ lacked P, and that only Kant could
have had P.
According t;;
The Origin View, each person has thi! distiDCtive necessary property:
that of having grown from the particular pair of cells from which this
penlOn in fact grt:w. 2
Thi, property cannot be flllly dininctive. Any pair of identical lwins both
from such a pair of cells. And any fertilized ovum might have later
split, and produced twins. The Origin View must be re:vised to meet Ibis
problem. But I need nol discuss this revision. It is enough for my purposes
that, on this view, Kant could not have grown from a different pair of cells.
Tire Cartesian V~W, Kant was a particular Cartesian Ego,
which had nO distinctive necessary properties.
On this view. a pcnw>o', identity has no connections with his physical and
mental characteristics. Kant might have beeo me, and vice versa, thousb, if
this had happened, no one would have noticed any difference. It is at worst
mildly controversial to claim. as I did, that we sbould reject this version of
tbe Cartesian View.
Two other views are closely related. On
The Descripti"e View, each person has several distinctive necessary
properties. These are this person's most imponant distinctive
properties, and they do nol include having grown from a particular
pair of cells.
In the casc of Kant, these properties would include his authorship of certain
boob. One version orthis view does not claim that Kant must have had all
these properties. Anyone with most of these properties would have been
The Descriptive Name View, every person's name means 'the person
who .. .'. For us now, 'Kant' means 'the person who wrote the Critique
of Pwe Reason, etc'. A particular person's necessary properties are
those that would be listed when we explain the meaning of this person's
Both this and the Descriptive View might be combined with the othe:r
version of CartcsLanism. Kant might be claimed to be the Cartesian Ejo
whose distinctive necessary properties include: the: authorship of certain
books. But the two Descriptive Views need not add this c1aim. J
One objection to the Dc:scriptive Views is that each person's life: could
have been very differe:nt. Kant could have died in his cradle. Since this is
pouible:, the authorsbip of certain books cannot be one of K.ant's necessary
ODe reply to this objection re:treats to a weake:r claim. It could be said:
'17te NOIf--Jdlntily Problem
119. Row OW' ltUlltity Depmds 011 When Wto Were Conceived
Though this property is not neccasary, it ill distincti...e. Kant might not
have written tbese boob. But, in any pollSible bistory in which a single
person wrote l.hese boob, tbis peROn would have been Kant.
this penon. But exact Ilimilarity is not the same as numerical identity,
u is shown by any two exactly similar things.
I need not discuss whether this. or some other reply, meets this objection.
Even ir the objection can be met, my Time-Dependence Oaim is true.
On botb Descriptive Views, Kant could bave grown rrom a different pair
or cells, or even had different pa.renls. This would ha\'C happened ir Kant's
mother had not conceived a child when she conceived him, and some other
couple hid conceived a child who later wrote the CrWque of Pure ReA.Toll,
etc. On the Descriptive Views, this child would have been Kant. He would
not have been called Kant. But this does not woI1)' bolders or these views.
They would claim lIlat, II tbis had happened, Kant would have bad both
different parenls and a different name.
Though they believe lIlat this might haw: happened, most holders or the
Descriptive Views Would 4l;Cept my claim that it would 1I0t ill fact have
happened. Ir they claim that it would have happened, they must accepl an
extreme version or Tolstoy's view, stated ill the epilojp.le or W.u and Pellee.
Ihal hiBtory does nOl depend on the decisions made by panicular people. On
this view, ir Napoleon's mothet had remained childless, history would have
provided a 'substitute Napoleon', who would have invaded RUNia in 1812.
And. ir K.ant's mother had remained childless, hutory would ha~ provided
another author ortbe Critiqw of PlITe Re(l3lHt. This view is too implausible
to be wonb discussing.
1ben: it another way in wbit:b bolders or tbe .Descripti..-e Views might
reject my claim. They might claim that Kant's necessary propenies were rae
less distinctive. They might ror instance merely be: being his mother's lint
child. This chum meets the objection that each perlOn's lire might ha~ been
very different. But this claim is also lOO implaU5ible to be wonh discussing.
I am the second ormy mother's three children. This claim implies absurdly
that, irmy mother had conceived no child when she in fact cona:i..-ed me, 1
would bave been my younger sister.
Consider next the possible history in which the Descriptive Views seem
most plausible. Suppose that Kant's mother had not conceived a cbild when
she conceived him, and that one montb later she concei..-ed a child who W4ll
a8Ctly like Kant. This child would ha..-e grown rrom a differenl pair or
cells.; but by an amazing coincidence, or a kind that never actually happens,
this child would ha..-e bad all or Kant's pRes. And suppose that, apan rrom
the ract and ~be effects of being born later, this child would have lived a lire
that was jU5t like Kant's, writing the Cririqw of Pwe Reason, etc.
On lhe Descriptive Views, this child would have bem Kant. Holders of
the Origin View might object:
Kant WIL8 a panicular persoD. In your imagined poNible history, you
have not &hown,that you ate rererring to thu particular person. In this
iinagiDc:d history, there woukl have bem SOmeoDC wbo was exactly like
These n:marks c1plain why the Origin View refers to the panicular pair of
cells from which a person grew.
A fifth view also makes sucb a dinel
~rcrence. On
The Backward Varia/ion Vu-w, this reference need not be: to the: point of
origin. or to the: cells from which a person grew. The reference can be
made: at any time in this person's life:. By making such a reference, we:
can describe how this person might have:: had II different origin.
Consider a holder of this view who, in 1780. is attendins onc of K.ant's
lectures. This penon might claim:
Kanl is the: person standing there. Kant might have had different
parenl.ll, and lived a different life up until the n:cent past. For this to
have ba:n what happened, all that is needed is thai this different life
would have led Kant to be now .tanding there.
This view mllSt make some rurther claims. But it meets the objection thai, to
juatiry a claim or identity, we need more than similarily. Holders or the
Origin View thererore need a different objection to the 8sd.ward Variation
View. For my purposes, I need not decide be:tween tbcie views.
On the Backward Variation View, Kant might have had a different
origin. But holden or this view would accept my claim ilial. in ract, this
would not have bappened. lhey would agn::e thal., ir Kant had not been
conceived witbin a month or the time wben be: WIL8 conceived. be would in
fact OC'Yer have existed.
I have now descritw:d all or the views about Our identity in different poss,ible
histories. 5 I discuss in endnote 6 bow these views are relaLcd to the different
views about our identity Ovef time On all or the plaus.ible views, my
Time-Dependmce Claim is true. This claim applies to everyone. You were
conceived at a certain time. It is in fact true thal, if you bad not been
collQCived a month or that time, YOIl would never have existed.
Unless we, or some global disaster, destroy lbe buman race, there will be:
people living later who do not now nisI. These are fllMe ~op{e. Science
has given to our generation gTC8t aMity both to affect tbese people, and to
predict these effects.
Two kinds or effect raise questions. We can affect the identities
orruture people, Of who the people are wbo will later li..-e. And we an affect
the number or ruture people. Tbese effects give us diffcm1t kinds of choic.e:.
121. How lmport(Ult Are 1M l"tef't!sls Of Future PtOPu.?
The NOII.lde"tiIY Prohu.m
In comparing any two acta, we can uk:
Would all and only the SlIme people
ever live in both outcomes?
Same Fwple Choices
Different People Choices
WOLlld Ihe same rlLlmber of people
eveT live in both outcomes?
Differefl/ Number
Different Number Choices affect both the number and the identities of
future people. Same Nwnber Choices affect tbe identities of future people,
but do not affect their number. Same People Choices affect neither.
Most of our moral thinkins is about Same People Choices. As I shall argue,
such choices are not as numerous as most of us assume. Very many of our
choices will in fact have lOme effect on both the identities and the number of
future people. But in most of these cases, bccawe we cannot predict what
the panicular effects would be, these effects can be morally ignored. We can
treat these C88CS U if they were Same People Choices.
In Bome cases we can predict that lOme act either mayor will be aiainst the
interests of future people. This can be true when we are makins a Same
People Choice. In such a case, whatever we choose, all and only, the same
people will ever live. Some of these people will be future people. Since these
people will exist whatever we choose. we can either hann or benefit thellC
people in a quite straightforward way.
Suppose that I leave some broken glass in the undergrowth of a wood. A
hundred years later this g1a&s wounds a child. My act hanns this child. If I
had safely buried the g1IlSS, this child would haw: walked through the wood
Docs it a moral difference that the child whom l hann does not now
On one view. moral priDciples cover only people who can uciprocafe. or
hann and beDdit each other. Ir J cannot be hanned or benefited by fhis
child, as we can plausibly suppose, the bann that J cause this child has no
moral importance. 1 assume that we should reject this view. 7
Some writers claim thal, while we ought to be concerned about effects on
future people. we arc morally justified in heinS less concerned about effects
in the furtbcr future. This is a common view in welfare economics, and cost­
benefit analysis. On this view, we can discOWlt the more remole effects of our
acts and policies, al lOme rate of" per cent per year. is called the Socwl
DiJcoWlt Rate.
Suppose we are considering how to dispose safely of the radio-active
matter called n.udear waste. U we believe in the Social Discounl Rate. we
shall be concerned with safety only in the nearer future. We shall not be
lroubled by the fact that some nuclear waste will be radio-active for
thousands of years. At a discount rale of five per cenl, one death next year
counts for more than a billion deaths in SOO yean. On this view,
cala.tlrophes in the further future can now be reiarded as morally trivial.
As this case: suggests. the Social Discount Rate is indefensible.
Remoteness in time roughly correlate! with some important facts. such as
predictability. But, as I argue in Appendix F, these corn:1alions are too
rough to justify the Social Discount Rate. The present moral importance of
future events does lIOt decline at a rate of" per cent per year. Remoteness in
time has, in itaclf, no more significance than mnoteT1CS$ in space. Suppose
that] ahool some arrow into a distant wood, where it wounds some person.
If J should have known that there might be someone in this wood, I lUl'I
guilty of gross negligence. Because this penon is far away, I cannot identify
tbe person whom I hann. But this is no e~cuse. Nor is it any excuse that this
person is far away. We ahould make the same claims about effects on people
who are temporally remote.
Future people are, in one respect. unlike distant people. We can affect their
identity. And many of our aetI have this effect.
This fact prodUCCB a problem. Before I describe (his prohlem, I shall
repeat lOme preliminary remarks. J llSSume that one person can be worse off
than anotber, in morally significant ways. and by more OT less. But] do not
llSSume that tbese comparilOns could be. even in principle, precise. I 8Siume
that there is only rough or partial comparability. On this usumption, il
could be true of two people that neither is worse off than the other, but this
would not imply that these people are exactly equally well off.
'Worse off' could be Laken to refer, either to someone'! level of happiness.
or more narrowly to his standard ofliving, or, more broadly, to the quality of
TIte NCNI-Idmtity Probwm
122. A YOWIg Oirl's Child
his life. Since: it is ~he broad~~, I shall often usc: the phrase 'the quality oftife'.
I also call IivCfi 'worth living'. This description can be ignored by
those who believe that there: could not be lives that are: not worth living. But,
like many olher people, I believe that there could be such lives. Finally, I
extend the ordinary usc of ~he phrase 'worth living'. If one of two people
would have a lower quality of !ife, I call his life to this extent 'less worth
yourself, but abo of your child. It will be wone for him if you have him
now. If you have him later, you will gi...e him a better start in life.'
We failed to persuade this girl. She had a child when she was 14, and, as
we predicted, abe gave him a had stan in life. Were we right to claim that
her decision was worse for her child? I( abe had waited, this particular child
would never have existed. And, despite iu bad start, his life is worth living.
Suppose lint that we do not belie...e that causing to exist can benefit. We
abould ask, 'If IlOmeone lives a life that is worth living. is thi8 wone: for this
person than if be had Dever existed?' Our answer must be No. Suppose next
that we bdi~e that causin(!, to exist Call benefit. On this view, this girl's
decision benefiu her child.
On both vic.... thilprl's decision was not worse for her child. When we
see this, do we chanp our atind about this decision? Do we cease to be1i~e
thai it would have been better if this girl had waited, 50 that she could give
to ber lint child a better ,tart' in !ife? I continue to have this belief, as do
most of thoee who con&i.der this case. Bul we caMOt defend this belief in the
nalural way that I sugpted. We cannot claim that this girl's decision was
worse for ber child. What is the objection to ber decision? This question
arises because, in the different outcomes, differco~ people would be born. I
shall therefOre call this the Non-Identity Problem. 9
It may be Il&id:
When considering future people, we must answer two questions:
(I) If we cause someone to exisl, who will have a life worth living, do
we thereby benefit this person?
(2) Do we also benefit this person if some act of OutS is a remote but
necessary part of the cause of his existence?
These are difficult questions. If we answer Yes to both, I shan say that we
believe thai cawing to exist can bt!nefit.
Some people answer Yes lo (I) but No to (2). These: people give their
second answer because Ihey use: 'benefit' in its ordinary sense. As I argucd in
Section 2~, we ought for moral purposes to extend our use: of 'benefit'. If we
answer Yes to (1) we should answer Yes to (2).
Many people: answer No to both these questions. These people might say:
'We benefit someone if it is true: thal, if we had not done what we did, this
would have bc:c:n wone for tbis person. If we had not caused someone to
ellist, this would not have bc:c:n wone for this person.'
I believe that, while it is defensible: to answer No to both these: questions,
it is also defensible to answer Yes to bolh. For those: who doubt this llC:Cond
belief I havc written Appendix G. Since: J believe that it is defensible both 10
claim and to deny that causing to exist can benefit, I shall di~uss the
implications of both views.
The 14· Year·OId Girl. This girl chooses to have a child. Because she is so
young, she gives her child a bad start in life. Though this will have bad
effects throughout this child's life, his life will, predictably, be wortb
living. If this girl had waited for sevcral years, she would haw: had a
different child, to whom sbe would have given a better start in life.
Since: such cases are becoming common, they raise: a practical problem.- They
also raise a theoretical problem.
Suppose thal we tried to persuade: this girl that she ought to wait. We
claimed: 'If you have a child now, you will soon regret this. If you wait, this
will be better for you.' She replied: 'This is my affair. Even in am doing what
will be wone for me, I have a right to do what 1 want.'
We replied: 'Thia is not entirely your all'air. You abould thirlk not only of
In one: sense, this girl's dedsion was wone for her child. In trying to
penuade this girl not lO bave a cbild now, we can use the pbrase 'her
child' and the pronoun 'he' to cover (JIIy child that sbe might have.
Tbex words ncc:d not refer to one particular child. We can truly claim:
'lfthill girl does not have ber child now, but waits and has him later, Ire
will not be the same particular child. If she has him later, he will be a
different child.' By using tbex words in this way, we can explain why it
would be better if this girl waits. We can claim:
(A) The objection to this girl's decision is that it will probably be worse
for her child. If she waited, she would prohably give him a better
start in !ife.
Though we can truly make this claim, it does not ellplain the objection to lhis
girl's decision. This becomes clear after she has had her child. The phrase: 'her
child' now naturally refers to this particular child. And this girl's decisiOn
was not WOtK for this child. Though lhere is a se:nse: in which (A) is true, (A)
docs nol appeal LO a familiar moral principle.
On one: of our familiar principles, it is an objection to someone's choice
that this choice will be worse for, or be against the interc:sts of, aoy other
particular penon. If we claim thal this girl's decision was wone: for her
child, we cannot be claiming that it was worse for a prarticulu person. We
cannot claim, of tbe girl's child, that her dc:cision Wal wone: for him. We
must admil that, in claim (A), the words 'ber child' do nol refer 10 her child.
TM NOI1·/del1tity Prohkm
(A) is Dot about what is good or bad for any of lhe particular people wbo
ever Ii\le. (A) appeals to a new principle, that must be explained and
If (A) seems to appeal 10 a familiar principle. this is because it has two
selUeS. Here is another example. A general ahows military skill if, in many
battJes, he always makes his the winning side. But there arc two ways of
doinS this. He might win victories. Or he might aJways, when be is about to
lose, change sides. A seneral shows no military skill if it is only in the
IICCOnd JlCI1se that be always makes his the winnins side.
To what principle docs (A) appeal? We should state the principle in a way
that shows the kind of choice to which it applies. These are Same Number
Choices, which affect the identities of fUture people, but do not affect their
number. We might suggest
The Same Nwnber Quolily Claim. or Q: If in eitber of two possible
outcomes the same nwnber of people would ever live, it would be worse
if those who li\IC are worse off, or ha\le a lower quality of life, tban tbose
who would have li\led.
Thill claim is plausible. And it implies what we believe about lhe I4.Ycar­
Old Girl. The: child that she has now will probably be worse off than a child
abe could have had later would have been, since this other child would have
had II better start in life. If this is true, Q implies that this is me worse of these
two outcomes. Q implies that it would have been better if this girl had waited,
and had a child later.
We may shrink from claiming, of this girl's lIClual child, that it would
ha\IC bcc:.n better if he had never existed. But, if we claimed earlier that it
would be better if this girl waits, this is what we mUll claim. We cannot
ooRsiatcntJy make a cJajm and deny thia same claim later. If (I) in 1990 it
would be better if this girl waits and hl18 a child later, tben (2) in 2020 it
would /tow! bent better if she had waited and had a child later. And (2)
implies (3) that it would ha\le been better jf the child who exiated had not
been her actual child. If we cannot accepl (3), we: mUSt reject (1).
I suggest that, on re6ection, we can accept (3). I believe that, if / was the
actual child of this girl, I could accept (3). (3) does not imply that my
existence is bad. or intrinsically morally ul:ldesirable. The claim is merely
thai. since a child born later would probably have had a better life than
mine, it would ha\le been better if my mother had waited, and had a cbild
later. This claim need nOI imply that I ought rationally to regret that my
mother had me, or that she ought rationally to regret this. Since it would
ha\IC been better if she had waited, she ought perhaps to have some moral
regret. And it is probably true that she made the outcome worse for herself.
But, e\len if this ia true, it does not ibow lhal sbe ought rationally to regret
ber 1ICl. all things considered. If she IO\les me, her actual child, this is enough
122. A YOIUIg Girl's Child
I.e block the claim that sbe is irrational if she does not have such regn:t.
Even when it implies a claim like (3), I conclude that we can accept Q.
Though Q is plausible. it does not solve the Non-Identity Problem. Q
covers only the cues wbere, in the different outcomes, the same number of
people would ever live. We need a claim that covers cases where, in tbe
different outcomes, different nwnbers would e\ler live. The Non-Identity
Problem can arise in these ClUlCS.
Because Q is restricted. it could be justified in several differenl ways.
There att several principles that imply Q. but contlict when applied to
Different Number Choices. We shall need to decide which of these
principles, or which set of principles. we ought to accept. Call what we
ought 10 accept T/teory X. X will solve the Non-IdentilY Problem in
Different Number Choices. And X will tell us how Q should be justified, or
more fully explained.
In the case of the 14.Ycar-Old Girl, we are not foreed to appeal to Q.
There are other facts to which we could appeal, such as the effects on other
people. But the problem can arise in a purer form.
Suppose that we are cboosing between two social or economic policies. And
suppose thal, On one of the two POJiciCi, the standard of living would be
slightly higher over Ihe next century. This effect implies another. It is not true
that, whichever policy we: choose, the same particular people will exist in the
further future. Given the effects of two such policies on the details of our
lives, it would increasingly over time be true thal. on the different policies.
people married different people. And, even in the same marriases. tbe
children would increa&ingly o\ICr time be conceived at different times. As I
have argued, chil~ conceiVed more than a month earlier or later would in
fact be different children. Since the choice between our two policies wolJld
affect the timing of later conceptions, some of the people who are later bOrn
would owe their existence to our choice of one of the two policies. If we had
chosen the other policy, these particular people would never have existed.
And the proponion of those later born who owe their existence to our choice
would, like ripples in a pool, steadily grow. We can plausibly assume thal.
af\er one or twO centuries, there would be nO one living in our community
who would have been bom whichever policy we chose. (It may help to tbink
about this question; how many ofm could truly claim. 'Even if railways jJnd
motor cars had never been in\ICnled, I would still have been born"!)
How does this produce a problem? Consider
Depletion. As a community, we must choose whether to deplete or
conserve certain kinds of resources. If we choose Depletion, the quality
TIw NOIf-Jdentily Problmt
123. How Lowerilfg Tiv QUQ/ily Of Uf~ Mlgnt & WQf'# FOI' N~OM 363
of life over the next two centuries would be slightly higher than it would
have been if we had chosen Conse.....ation. But it would laler, for many
centuries, be much lower than it would have been if we had chosen
Conse.....ation. This would be because, at the stan of this period, people
would have to lind ahematives for lhe resourc:cs lhat we bad depleted. It
is worth distinguishing two versions of lhis case. The effects of lhe
different policies would be as shown below.
Now- 200 years­
Lesser Depletion
Now -
200 years ­
We could never know, in such detail, lhal lhese would be lhe effects of two
policies. But this is no objection to this case. Similar effects would sometimes
be predictable. Nor does it matter that this imagined case is artificially
simple. since this merely clarifies the relevant questions.
Suppose that we choose Depletion, and that this has either of lhe two
effects shown in my diagram. Is our choice WORe for anyone?
Because we chose Depletion, millions of people have. for several centuries,
a much lower quality of life. This quality of life is much lower. not than it is
now, but than it would have been if we had chosen COnse ation. 1bcse
people's lives are wortb living; and. if we had chosen COnse ation. these
particular people would never have cxiated. Suppoac that we do nolulumc
that causing 10 exist can benefit We !hould ask, 'If particular people live lives
that an: worth living, is this wone for these people than jf they had never
existed?' Our answer must be No. Suppoac next that we do usumc that
C8.uaioS to exist can benefit. Since these future people's lives will be: worth
living, and they would never have existed if we had choaen CODlCl"Yation, our
choice of Depiction is nOL only not wone for these people: it benefit! lhem.
On both answers, our choice will not be wone for Lhcsc future people.
Moreover, when we understand the case, we know that this is true. We
know that, even if it greatly lowers the quality of life for several c:enturies,
our cboice will not be worse for anyone who ever lives.
Does this make a moral difference? Then: arc three views. It might make
aU lhc difference, or some diffcreooe. or no difference. There might be no
objection to our cboice, or some objection, or the objection may be just as
Some believe that wluJl Lr bad "'JUt be bad/or SOIfU!OM. On this view, there
is no objection to our choice. Since it will be bad for no one, our choice
cannol have a bad effect. The great lowering of the quality of life provides
no moral reason not to cboose Depletion.
Certain writcn accept this conclusion. I I But it is very implausible. Before
we consider cases of this kind, we may accept the view that what is bad must
be bad for someone. But lhe case of Depletion shows, 1 believe, lhat we
must reject this view. The great lowering of the quality of life must provide
SOIfU! moral reason not to choose Depletion. This is believed by most of
lhose who consider cues of this kind.
If this is wbat we believe, we should ask two questions:
(1) What is the moral reason nol to choose Depletion?
(2) Does it m.ake a moral difference that this lowering of the quality
of life wiD be WOIW for no one? Would this effect be worse, having
grealer moralwe:igbl, if il was WOIW for particular people?
Our need to answer (I), and other similar questions, I call the Non-Identity
Problem. Thit problem ariae3 because lhe identities of people in the further
future can be very easily affected. Some people believe that this problem is a
mere quibble. This reaction is unjwtified. TIw: problem arises because of
superfic:ial facta aboul our reprod\K:tive system. But, though it arillCS in a
superfic:ial way. it is a rgJ problem. When we are choosing between two
IIOCiaI. or economic policies, of tbe kind that I described, it is f10t tn.e that, in
the further future, the same people will exist whatever we choose. It is
therefore IIOt trIM! that a choice like Depletion will be against the interests of
future people. We caQl!oot diamilll this problem with the pretence that this is
We panty AMWer question (I) if we appeal to Q. On this claim, if the
__________ . __J
TJw Non-lde"tity Problem
numbers would be the same, it would be worse if those who live have a lower
quality of life than thoee who would have lived. But the problem can arise in
cases where, in the different outcomes, there would be different numben of
people. To cover these ca&C8 we need Theory X. OoJy X will explain bow Q
should be justified, and provide a full solution to our problem.
Can we solve our problem by appealing lo people's rights? Reconsider the
14-Year-Qld Girl. By having her child 30 young, she gives biro a bad start in
life. It might be claimed: 'The objection to this girl's dteision is that sbe
violates her child's right to a good start in life'.
Even if this child has this right, it could Dol have been fulfilled. This girl
could not have had tnil child when she was a mature woman. Some would
claim that, since: this child's right could not be fulfilled, this girl cannot be
claimed lo violate his right. The objector might fCPly: 'It is wrong to cauae
3Omeone to exist if we know that this person will have a right that cannot be
fulfilled.' Can this be the objection to this girl's dcciIion?1J
Some years IIgo, a British politician welcomed the fact that, in the
previous year. there had been fewer teenage pregnancies. A middle-aged
man wrote in anger to TIle Times. He had been born wben his motber was
only 14. He admitted lhat. because hi, motber was 30 yOWlg, his early years
bad been hard for both of them. But his life was now well wortb living. Was
the politician suggesting that it would haw: been belter if he bad never been
born? This suggestion sccmcd (0 him. outrageous.
The politician was, implicitly, suggesting this. On the politician's view, it
would have been belter if t.biI man's mother bad waited for several yea"
before having children. I believe that we sbould aa:ept this view. But can we
plausibly aplain this view by claiming that this angry man had a right thai
was not fulfilled?
I believe that we cannot. Suppoee that I have a right to privacy. I ask you
to marry me. If you aa:ept. you are not acting wrongly, by violating my
right to privacy. Since: I am glad that you act as you do, with respect to you
( waive this right. A similar claim applies to the writer of the angry letter to
Tiv Times. On the suggestion made abow:, this man hall a right to be born
by a mature woman, who would giw: him a good start in life. This man',
mother acted wrongly because she caused him to exist with a right thai
cannol be fulfilled. But this man's letter thows that be was glad to be aliw:.
He denies that his mother acted wrongly because of what sbe did to him. If
we bad claimed that her act was wrong, because he bas a right that cannot
be fulfilled, be could have said, 'I waive righl'. This would haw:
undermined our objection to his mother's act.
It would have been better if this mao's mother had waited. But this is not
because of whal ,he did to ber actual child. It i' because of what &be could
124. Why An Appeal To RiglHS Cannot Wholly So/ve TJw Problem 365
have done for any child that she could have bad when 'be wa6 mature. The
objection mwl be that, if she bad waited. she could have given to some
other child a beUer Slart in life.
Return now 10 the Case of Depiction. Suppose thai we choose Greater
Depiction. More than two centuries later, the quality of life is much lower
than it would ha...c been if we had chosen Conservation. But the people who
will then be living will have a quality of life that is about as high as Dun will
on average be over the nc;\t century. Do these people have righ1.5 to which an
objector can appeal?
It might be claimed that lbC$C people have a right 10 their share of the
resources that we haw: depleted. But people do not have rights to a share of
a particular resource. Suppose that we deplete &Orne resource, but invent
lccbnology that will enable our SUCOCSIOn, though they lack this resource,
to have the aame range of opportWlities. There would be no objection to
what we haw done. The most lbat c:ould be claimed is that people in each
generation bave a rirt to an equal rllllge of opportunities, or 10 Illl equally
high quality of life. I
If we cboose Greater Depletion, those who live more thllll two cenluries
later will have fewer opportunities, and a lower quality of life, than some
earlier and some later genenalions. If people have a right to equal opportuni­
ties, and an equally high quality of life, an appeal to these rights may provide
some objection to our choice:. Those who live more than two ce:nturies later
c:ould nOl possibly have had greater opportunities, or a higher quality of life.
If we had chosen otherwise, these people would never have e~isted. Since:
their rights could not be fullilled, we may not violate Ihor rights. But, as
before, it may be objccted that we cause people to e~ist with rights thal
cannot be fulfilled.
It is not clear this is a good objection. If these people knew the facts,
they would not regret lhal we acted as we did. If they were glad 10 be alive,
Ihey mighl react like Ihe man who wrolc to The Tim£s. They might waive
lheir righls. But, since: we cannot assume that this is bow they would all react,
an appeal to their rights may provide some objection to our choice.
Can this appeal provide an objcction 10 our choice of uSJer Depletion? In
this case, those who live more than two centuries laler have a much higher
quality omfe than wedo now. Can we claim that lhese people have a rignlto
an even niglvr quality of life? I believe that, on any plausible theory about
rights, the answer would be No.
II will hetp to imagine away the Non-Identity Problem. SuPPOse thlll our
reproductive system was very different. Suppose that, whatever policies we
followed, the very same people would live more than two centuries later. The
objection to our choice would then be that, fot lhe sake of small benefits to
ourselves and our Children, we prevent many future people from receiving
very much greater benefits. Since tbese future people would be beUer off than
us, we would nol be acting unjustly. The objection to our choice would have
La appeal to the Principle of Utility.
'T1v /'{OfI-ltktltily Problem.
125. Does The Fact OfNOIl·/detl,;ty MaJu A Moral DijJereflce?
Could this objection appeal to rights? Only if, like Godwin, we p~nt
Utilitarianism as a theory about righll. On Godwin's view, everyone haa a
riglll to get what the Principle of Utilily implies that he should be given.
Most of those who believe in rights would reject this view. Many people
explain rights as what cOfUtraill, or limit, the Principle of Utility. These:
people claim thai it is wrong to violate certain rights, even if this would
greatly increale tbe net sum of benmll minus burdens. On lucb a theory,
IOI11C weight ia given to the Principle of Utility. Since such a theory is not
Utilitarian, this principle is better called the Prillciple of Benejiceflce. This
principle is one pan of sucb a theory, and the claim that we have certain
rightll is a different pan of this theory. I shall assume that, if we believe in
rights, this is the kind of moral theory that we acc:ept.
Return to the cue where we imagine away the Non-Identity Problem. If
we rejc:ct Godwin's view, we could not object to the choice of Lesaer
Depletion by appealing to the rights of thoae who will live in the further
future. Our objection woukl appeal to the Principle of Bcneficcoce. 11le
objection would be that, for the sake of small benefits to ounelvcs and our
children, we deny, to people better off than us, very much greater benefits.
In calling this an. objection, I need not claim that it &bows our cboice 10 be
wrong. I am merely that, since we deny these people very much
greater benefi.ts, this provides 100II moral reason not to make Ibis choice.
If we now restore our actual reproductive system, this reuon disappean.
Consider the people who will live more tban two centuries later. Our choice
of LesllCr Depletion does not deny theae people lUIy benefi.\. Ifwe bad choSC1l
Conaervation, Ibis would not bave benefited these people, since they would
never have existed.
When we assume away the Non-Identity Problem, our rason not to
make this choice i. explained by an. appeal, not to people'. rights, but-to the
Principle of Beueficcnce. When we restore the Non-Identity Problem, this
mI80n disappears. Since this reason appealed to the Principle of
Bcneficc"Dce, what the probJcm &bows is that thia principle is inadequate,
and muat be revised. We need a better aocount of bene6cencc:, or what I call
One pan of our moral theory appeals to beneficeDce; another pan
appeals to people's rights. We sbould therefore not expect that an. appeal to
rights could fill the gap in our inadequate Principle of BcncfK:ence. We
&bould expect that, ., I bave claimed, appealing to rights cannot wholly
solve the Non-Identity Problem.
what we believe about the other question tbat I mentioned. Our choice of
Depletion will be wone for no one. Docs this make a moral difference?
We may be able to remember a time when we were concerned about
effccts on future generations. but had overlooked the Non-Identity
Problem. We may have thought that a policy like Depletion would be
against the interests of future people. When we saw that this was falae, did
we become less concerned about effcetl on future Fnerations?
WIlen I I8W the problem, I did not become less concerned. And the I8JIlC
is true of many other people. I shall sa)' that we accept the No-Difference
In trying to revise our Principle of Beneficence---trying to lind Theory X­
we muat consider CMeI wbere, in the different outcomes, different numbcn
of people woukl exQl. Before we turn to t.bae CMeI, we can uk
11 is worth considering a different example:
The Medical Programmes. There are two rare conditions, land K, which
cannot be detected without special tests. If a pregnant woman has
Condition J, this will cause the child she is carrying to have a certain
handicap. A simple Ireat.ment would prevent this effect. If a woman has
Condition K when she conceives a child, this will cause this child to have
the same particular handicap. Condition K cannot be lre.atcd, but
always disappears within two months. Suppose next that we have
planned two medical programmes, but there are funds for only one; so
one must be cancelled. In thefinlt programme, millions of women would
be tested during pregnancy. Those found to have Condition J would be
treated. In the second programme, millions of women would be tested
when they intend to try 10 become pregnant. Thoae found to have
Condition K would be warned to postpone conception for at least two
months, after which this incurable condition will have disappeared.
Suppose finally that we can predict that theae two programmes would
achieve results in as many caaes. If there is Pregnancy Testing, 1,000
children a year will be born nonnal rather than handicapped. If there is
Preconception Testing, there will each )'ear be born 1,000 nonnal
children ralher than a 1,000, different, handicapped children.
Would these: two programmes be equally worthwhile? Let us note carefully
wbat the differeDtC is. As a result of either programme, 1,000 couples a )'C8I
would have a normal rather than a bandicapped child. Thcsc would be
different couples, on the two programmes. But tina: the numbenl would be
the same, the effects on the parents and on other people would be morally
equivalent. If there is a moral difference, this can only be: in the effectll on
the cbildren.
Note next that, in judging lhCllC effects, we need have no view aboul the
moral status of a foetua. We can suppose that it would take a )'C8I before
either kind of testing could begin. When we choose between the two
programmes., none of the chil~ has )'tit bc:co conceived. And all thoae
who are cobDeived will become adultll. We are therefore considering effects,
TM HOIt-/dtnttity ProlM,"
125. D~1 TM Fact Of No,,~ldelltityMalee A Moral Differellce?
not on present foetuses, but on future people. Assume next that the
handicap in question, though it is not trivial, is not so severe: as to make: life
doubtfully worth living. Even if it can be against our interests to have been
born, this is not true ofthose born with this handicap.
Since we cannot afford both programmes, which should we cancel?
Under one description, both would have the same effect. Suppose thai
Conditions J and K are the only causes of this handicap. 1be incidence is
now 2.000 among those born in each year. Either programme would halYe
the incidence; the rate would drop to 1,000 a year. The difference is this. If
we decide to cancel Pregnancy Testing. il will be true of those who are later
born handicapped that, but for our decision, theY would have been cured.
Our decision will be worse for all these people. Ir instead we decide to cancel
Pre--Conception Testing, tbere will later be jut as many people who are
born with this handicap. But it would not be ltUe of these people that, but
for our decis.ion, they would have bc:cD cured. These people owe their
existeDcc to our decision. If we had not decided to cancel Pre-Conception
Testing. the parents of these handicapped children would nol have had
tJrem. 1bey would have later had different children. Since the liyes of these
handicapped children IU'e worth Jiving. our decis.ion will nol be worse for
any of them.
Does this make a moral difference? Or IU'e the two programmes equally
worthwhile? Is all that matlen morally bow many future lives will be lived
by normal rather than handicapped people? Or does it also matter whether
tbe8e lives would be lived by the very same people?
We should add one detail to lhe case. If we decide to cancel Pregnancy
Testing, those who IU'e later born handicapped might know t.hat, if we had
made a different decis.ion, they would haye bc:cn cured. Such knowledse
might make tbeir handicap h&rder to bear. We should therefore assume
that, thOUgh it is not deliberately concealed, these people would not know
this fact.
With this detail added. I judse the two programmes to be equally
worthwhile. I know of some people wbo do not accept this claim; but I
know ofmore who do.
My miCtion is not merely an intuition. It is the judgement that I miCh by
reuooing as follows. Whichever programme is cancelled, there will later be
jut as many people wilh this handicap. These people would be ditl'erent in
the two outcomes that depend on our decision. And there is a claim that
applies to only ODe of tbe8e two groups of handicapped people. Though
they do nol know this fact, the people in one group could haYe bc:cn cured. J
therefore aRk: 'If there will be people with some handicap, the fact that they
IU'e handicapped is bad. Would it be wor1e if, unknown to them, their
handicap could have been curedT This would be worse if this fact made
Ibese people worse off t.han people whose handicap could /fot have been
cured. But this ract does not have this effect. If we decide to cancel
PreJIIIIDt:)' TestiD& there will be a group of handicapped people. If we
decide to cancel Pre-Conception Testing, there will be a different grOUp or
handicapped people. The people in the first group would not be .....orse off
than the people in the second group would haye been. Since this is so, I
judge these two outcomes to be morally equivalenl. Gi\lcn the details of the
case, it seems to mc im:lcvant that one of the groups but nol the other could
haye been cured.
This fact W()uJdhave been relevant if curing this group would have reduced
the incidence of this handicap. But, since we have funds for only one
programme, this is not true. If we choose to cure the lint group, there will
later be just as many people with this handicap. Since curing the first group
would nol reduce the number who will be handicapped, we ought to choose
10 cure this group only if they have a Slrongerclaim to be cured. And they do
not haye a stronger claim. Irwe could cure the second group. they would haye
an equal claim to be cured. Ir we chose to cure the first group, they would
merely be luckier than the second group. Since they would merely be luckier.
and they do not haye a stronger claim to be cured. I do not belieye that we
ought to choose to Cure these people. Since it is aho true that. if we choose to
cure these people. thu will no{ reduce the number of people who will be
handicapped, I conclude that the two programmes are equally worthwhile. Ir
Pre-eonception Testing would achieYe results in a few more cases, I would
judge it to be the better programme. 16
This malCbes my reaction 10 our choice of Depletion. I belieye that it
would be bad if there would later be a great lowering of lhe quality of life.
And J believe that it would not be worse if the people who later Iiye would
themselyes haye existed if we had chosen Conservation. The bad effect
would nol be worse if it had been, in this way, worse for any panicular
people. In considering both cases, I accept the No-Difference View· So do
many other people.
I have described two cases in which I, and many othen, accept the
No-Difference View. If we are right 10 accept this view, this may haye
important theoretical implications. This depends on whether we belieye
that, jf we cause someone to exist who will haye a life worth living. we
thereby benefit this person. If we believe this, J cannot yet state the
implications oftb.e No-Difference View. since these will depend on decisions
that I haye not yet discussed. But suppose we believe that someone
to eml cannot benefit this penon. If this is what we believe. and we accepl
the No-Difference View, the implications are u follows.
I baye suggested that we should appeal to
Q: If in either of two po$5ible outcomes the same number or people would
ever liye, it will be worse if those who Iiye IU'e wone off, or ha1le a lower
quality of life, than those who would haye liYed.
Consider nell
n.. NDlt-/dJnttlly_ProblDn
125, Does TM Fact 0/ NOlf-r/Mrltiry Mgq A Moral DiJI~m,u?
TM P,rNII·Aff,e'lng Vkw. or V: It will be worse if peopk are affc:eted
for the worse.
in pet'IOn-affcetin& terms, Its fundamental principles will not be concerned
with whether our acta will be good or bad for tl\oae people whom they
affcct. Theory X will imply that an elfect i. bad if il i. bad for people. BUI
this will not tie why this efroct is bad.
Remember Dcxt that theae claims bSume thilt causing to exist cannOl
In Same People Choka, Q and V coincide. When we are col1lideriaa thcIe
choicca, thOle who live are the same in both outcomea. If these peopk are
worse oil', or have a lower quality of life, they are affected for the WOI'1lC.,
and vice vena. 17 Siacc Q and V bere coincU:k:. it will m.llke ao d.ifrermQC to
wlUcb we appe:aJ.
The two claiml conflict only in Same Number Choioci. These are what thil
chapter hal discusIcd. Suppose that we accept the No-Difference View. 10
conlidering theae choica, we lhaJl then appeal to Q ralMr ,IsDn V. if we
chOOIC Depletion, this will lower the quality of life in the further future.
Accordina to Q, our choice hal a bad effect. But, because of the facti about
identity, our choice wiD be bad for no oae. V does not imply our choice
hal a bad effect. Would thil effect be worse if it- war WOl1lC for particular
people? If we appaJed to V rather than Q, our anlwer would be Yea. But.
liocc we believe the No-Diffm:acc View, we answer No. We believe that V
gives the wrong answer here. Aad V g;ve:s the wrong answer in tbe cue of the
Medical Propamma. Q deac:ribes the effeeu that we believe to be bad. Aad
we believe that it makes no moral difference whether theae elfccll are alJo bad to V. V dra..... moral diltinction. where, on our view, 00_
di.tiactiODl thouJd be drawu.
In Same Peopk Choices, Q and V coincide. In Same Number Chom,
where thcIe cJaima conftict, we accept Q rather than v. When we make thcIe
two Idadaofchoicc., we Ihan therefore have 00 use for Y.
TbcR ranain the Difl'eteJlt Number Chom, wbitb Q does not cover. We
wI! here DOcd Theory X, I have not yet diIcUI8Cd what X &bould claim. But
we can prtdict the f9l&owing. X will imply Q in Same Number Cboica.
We ClUl aJso predict that X wiD have the aame rdatiOD to V. In Same
Peopk Choka, X and V will coincide. It will here make: no difl'ermce to
which we appeal. "'I'1lae are lbe choica with which mOil of our moral
thinking ill conccroed. This ClpiaiDl the pJauaibility of v. TbiI part of
morality, t:bc part QCIna:mcd with be~, or human well.beiQl, ill
usually thOUpt of in what I Ihan ~1 ptrlMMJjfecIIIJ, termI. We appeaIlo
peopk's intCtell&-to what is good or bad for thOle people whom our acu
affoct. EvtD aftc:r we have fouod Theory X. we miJbt continue to appoal to
V in mOil euca, merdy 'oecaVit it ill mort flUDiUar. But in aome cua X and
V will coDftict. 'Ibcy may coD8ict when we an: m.a.kioI 'Same and DiJl'creot
Number Choic:a. ADd, wbeaeYer X and V conftiet, we IbaIJ appeal to X
ralMr IJwn V. We thNl ~e that. it tome dl'ect iI bad to X,it
maka no moral difl'crCDCC whether it ill a1Io bad aa:ordiDa: to V, A, before,
V dra..... a moral diltiactioa where, on our view, DO distinctioa 'hould be
draWD. V ill like the claim that it ill wrona to c:oalavc whita, or to dcuy the
vote to aduJt ma1cI. We Iha1J thus coDClude that tbiI part of morality, the
part conccmcd with bcne8oeoce aDd human wdl-beina. cannoc be ap1aiDed
benefit. This assumption if; deferulible. If we make this IUIlumption. these
claims Ihow thatmaoy moral theories need to be revised, since these theories
imply that it must make a moral dilfcrcnoe whelher our ilca arc good or bad
for those people whom they alfect. '1 And we may need to revise ow beliefs
about certain common cases. One example miJbt be abortion, But most of
our moral thinkin, would be unchanged. Many significant relatiofts hold
only between particular people. These include our relationl to those to whom
we have made promises. or owe ifBtitude. or our parenh. pupils, paticou.
clients, and (if we are politiQans) those whom we: represent. My remarks do
not apply to such relations, or to the special obligations which they_produce.
My remarkl apply only to our Principle of BcncficeDCC: to our general moral
reuon to benefit other people, and to protect them from barm,
Since my remarks apply only to thil principle, Bnd we lball have changed
our view only in lOme cues, thil change of view may seem unimportant.
1bia ill nol so. Consider once apia UUI (too grandiose) awoBY: In
ordinary caICI we (;8D accept Newton'. Laws. But Dot in iill C8ICI. And we
now accept a different theory.
[ .J
126. CaJul1lg Predictable CGliUtroplw 111 77u Fwtlwr Future
I shall now summarize what I have claimed. It is in fact lrue of everyone that.
if he bad not been conceived wilhin a month of the lime when he was
conceived. he would never have ellisted. Because this is lNe, we can easily
affect the identities offutun: people, or whO the people ate who williaur live.
If a choioe between two social policies will affect the standard of livina: or the
quality of life for about a century, it will affect the details of all tbe lives that,
in our community, are laur lived. As a resUlt. some of those who later live
will owe their existence to our choioe of one of these two policies. Aflcr one
or two centuries, this wiU be true of evuyone io our community.
77u NOII-ldetulty ProbWm
ThiI fact produtel a problem. One of LbeIc: two policicr may, in the
fWtbcr fu~ e-Ule a areat Iowcriq of the quality of lite. This would be
the dl'ect of the policy I cali Depiction. ThiI elrect" iI bad, aDd providcl a
moral l'C8IOn not to chooIe Depletion. But, bCll;:ause of the fact just
mentioned, our choioe of Depletion will be WOtIC fot no one. Some people
belltw: chat a choice ClLDDOt haw bad dl'ClCtI if tbiI choice will be WOtIC fot
DO one. The Cue of DepCtiOD mows chat we mUit reject this vi". And thiI
iI &hOWD more forccfuJ)y by the Cue of the R.iHy Policy. One effect of
cboo.inJ this policy iI a catutrophe that kill. thousands of people. This
efl'ect iI clearly bad, even thoup our choice will be wone for no one.
SiDce that two choices will be wane for DO one, we need to ellpwn wby
we have a moral reBIOD not to make theIe cbom. This ptoblem aria
bCll;:aUlle, in the differcat oulcomCl, difl'crcot people would WIt. I therefore
call1hil the Non·IdeDtity Problem.
I asked whether wa C8.D aolWl tbiI problem by appealina: to people', righla.
I lUJUCd that, even in the cue of the Risky Policy, the objection to our
choice cannot appeal oaly to peopk's righll. The objection mUlt" in part
appeal to a claim like: Q, wbicb compares diffen:at possible lives. Aad we
cannot plausibly appeal to riabta in ellplainina: the objclction to our choice of
Lcucr Depiction. Even after the pat loweriDJ of the quality of lite, thOlle
who will be liviDJ will be much. better 00" than we are now. TbeIe people
cannot be claimed to have a ript to the even higher qUAlity of life that
diO"en:at people would have enjoyed if we had cboam CoDlCrVation. If we
imqinc away the Non-Identity Problem, the objection to our cboioc would
appeaJ to our PriDeiple of 8cDefk::eoce. To solve the Non-Identity Problem,
we mUit revile tbiI priacipkl.
0.. ....oed principle;' Q. the Same Number Quality Claim. A<co<dU>a to
Q. if in eitbe:r of two outcoma there would be the IIlUDC number of people, it
woukl be worse if those wbo live are wane off, or have a lower quality of life.
than thOle wbo would have li'tOd. We Deed a wider priDCiple to cover cues
wbcftl, in the difI'ueot outcom8l, chcrc would be difl'en:at oumben or prople.
This needed priDciple I call Theory X. Only x will fuUy solve the Non­
Identity Problem.
Doa the fact of DOn.identity make a moral diiJerence? When we see that
ourchoic:e of Depletion will be WOtIC for DO one, we may believe that tbeR'
i, leu ob.icc:tion to our choice. But I beJ~ that the objection iI just &I
ItroDJ. And I have & similar bclict wben I COIDpatC the efl'ecll of the two
Medic:aJ Programmes. Thia bdH:f I call the No Difl'ercnce VIeW. Thoup I
know of lIOIDC people who do QO't accept tbiI vi", I know of more wbo do.
If we BQXPt the No DiB'e:tmai View, aDd believe chat to exist
cannot beadit, thiI baa wide theoretical implications. We can predict that
Theory X will. not take a petIOD-&ffectin form. The bat theory about
bcncficeDce will. DOt appeal to what ia aood or bad for thOle prcopIc: whom
our IICU &KeeL
i I