PHIL2617/PHIL3617
Week 2
plan
• What makes killing wrong? 4 theories
• Is abortion wrongful killing? Is a foetus the
kind of being that it is seriously wrong to kill?
Recap wrongness of killing
Sanctity of life. It is prima facie seriously wrong to
kill a normal adult human being
This is ambiguous between
1. It is seriously wrong to kill a member of the
biological species homo sapiens
2. It is seriously wrong to kill a rational and self-
aware being—i.e. a psychological ‘person’
Why is killing a person (especially) wrong?
4 ethical theories
1. Classical utilitarianism
2. Preference utilitarianism
3. Rights-based
4. Autonomy-based
Classical utilitarianism
• you ought always perform the
action that results in the
greatest amount of overall
happiness in the world
• ‘overall happiness’ =
happiness minus any
unhappiness
classical utilitarianism
• killing is wrong because it results in less overall
happiness in the world
• Killing a person is worse (under certain
circumstances) because it produces more
unhappiness than killing a non-person
• direct reason against killing: suffering to victim
• indirect reasons: creates widespread social anxiety
objection
• Wouldn’t killing still be
wrong, even if it didn’t
have any bad
consequences?
• Example: secret,
painless killing
• critical and intuitive
levels of thinking
• It will have better
consequences in the
long run if we adhere to
a principle of respecting
the lives of people who
want to go on living
than if we do not
preference utilitarianism
• you ought always perform the action that
results in the greatest amount of desire-
satisfaction in the world
preference utilitarianism
• Killing is wrong because it frustrates desires
• Killing a person frustrates more desires than
killing a non-person, so killing a person is worse
objection
• what if a person’s preference for continued life
is outweighed by stronger or more numerous
preferences to the contrary?
rights-based
• killing a person is wrong because it violates
the person’s rights
• only beings who are, or once were, capable of
desiring to go on living (i.e. persons) can have
a right to life (Tooley)
Tooley
• “The basic intuition is that a right
is something that can be violated
and that, in general, to violate an
individual’s right to something is
to frustrate the corresponding
desire. Suppose, for example,
that you own a car. Then I am
under a prima facie obligation not
to take it from you. However, the
obligation is not unconditional: it
depends in part upon the
existence of a corresponding
desires in you. If you do not care
whether I take your car, then I
generally do not violate your right
by doing so.” (‘Abortion and
Infanticide’)
autonomy-based
• Killing a person (against their will) is wrong
because killing disrespects the person’s
autonomy
• ‘Autonomy’ refers to the capacity to choose
and to act on one’s own decisions
RECAP
Why is killing a person (especially) wrong?
1. Hedonistic utilitarianism
Killing is a person is esp. wrong because it results in less net happiness
in the world
2. Preference hedonism
Killing a person is esp. wrong because it frustrates more desires
3. Rights-based
Killing a person is esp. wrong because it violates the person’s rights
4. Autonomy-based
Killing a person is wrong because killing disrespects the person’s
autonomy
The morality of abortion
• When, if ever, is abortion morally permissible?
The legality of abortion
The legality of abortion
USA 2024
Overview of traditional positions
1) Liberal-Feminist (“Pro-
choice”)
• A foetus is not a
person (rational, self-
conscious), so killing it
is not seriously
wrong; and
• The interests of the
mother outweigh
those of the foetus
Overview of traditional positions
2) Conservative (“Pro-
Life”)
• Killing a foetus is
morally equivalent
to murder, and
permissible only in
exceptional
circumstances e.g.
to save mother’s
life
traditional conservative argument
P1. It is wrong to kill an innocent human
being (Sanctity of Human Life Principle)
P2. A foetus is an innocent human being
————————————————————
C. Therefore, abortion is wrong (From P1
and P2).

standard liberal response
• The conservative argument commits a fallacy of
equivocation.
• ‘Human being’ is ambiguous between ‘member of
the species Homo sapiens’ and ‘person’
• If ‘human being’ means ‘member of the species
Homo sapiens’ then, while P2 is true, P1 is
implausible: only persons have a serious right to
life.
• If ‘human being’ means ‘person’ then P1 is
plausible, but P2 is false: the available evidence
suggests a foetus is not actually a person.
The Potentiality Argument
P1. It is wrong to intentionally kill a human
being that is either an actual or a potential
person
P2. A human foetus is a potential person
————————————————————
C. Therefore, it is wrong to intentionally kill a
human fetus (From P1 and P2)
Is potentiality morally significant?
Voting Graduation
The orthodox liberal argument
P1. Only (actual) persons—i.e. self-conscious,
rational beings—have a serious right to life
P2. A foetus is not a person
—————————————————————
C. Therefore, a foetus does not have a serious
right to life. (From P1 and P2)
Abortion and Infanticide
Foetal Development
Conception:
Sperm penetrates egg.
First trimester: 1-14 weeks
The embryo at 3.5 weeks
By week 7: all essential organs
have at least begun to form.
Foetal Development
Foetus at 10 weeks, 3.2”
•Foetus achieves human form
By week 12 the foetus can make a
fist with its fingers
Second Trimester: 14-28 wks
Foetus at 13-16 weeks, 6”
•the fetus makes active
movements
•At 20 weeks ‘quickening’ occurs
(the mother can feel the foetus
moving)
Foetal Development
• Weeks 24 - 28, 15”
• the foetus has a hand and startle reflex
(spontaneous movement)
• Rapid brain development
• nervous system developed enough to
control some body functions
(sentience?)
• a baby born at this time is potentially
viable (may survive outside the womb),
but the possibilities for complications
and death remain high
• Third trimester: 28-40wks
• At 36 weeks has a high chance of
survival, but may require some medical
interventions. Considered full-term at
37 weeks
Intrinsic vs. “all things considered” wrongness
• abortion and infanticide may be intrinsically morally
equivalent (i.e. setting aside side-effects)
• but it does not follow that they morally equivalent all
things considered, for side effects may differ crucially
unpalatable consequence?
Abortion and Infanticide
“speciesism”
Don Marquis
• Aims to “set out an
argument that purports
to show, as well as any
argument in ethics can
show, that abortion is,
except possibly in rare
cases, seriously immoral,
that it is in the same
moral category as killing
an innocent adult
human being.” (p. 24)
A fresh approach
• What is the best
explanation for our firm
belief that killing a
normal adult human
being in normal
circumstances is morally
wrong?
The best explanation
• Killing is prima facie
wrong because it
prevents a valuable
future, a ‘future like
ours’
• A sufficient condition
for wrongful killing
a ‘future like ours’
• “What primarily makes killing wrong is neither its
effects on the murderer nor its effects on the
victim’s friends and relatives, but its effect on
the victim. The loss of one’s life is one of the
greatest losses one can suffer…To describe this as
the loss of life can be misleading, however. The
change in my biological state does not by itself
make killing me wrong. The effect of the loss of
my biological life is the loss to me of all those
activities, projects, experiences, and enjoyments
which would otherwise have constituted my
future personal life.” (4)
Don Marquis, ‘Why Abortion is Immoral’
P1. What makes killing a normal human adult
prima facie seriously immoral is that it causes
the victim to lose a future like ours.
P2. Abortion causes a foetus to lose a future like
ours.

C. Therefore, abortion is prima facie seriously
immoral. (From P1 and P2)
‘future like ours’
• Is it the foetus or the (potential) person that has the
valuable future? (McInerney)
Best explanation?
Marquis’s reply to the ‘contraception’ objection
• “The wrong of killing is
primarily a wrong to the
individual who is killed;
at the time of
contraception there is
no individual to be
wronged.”
the “totipotency problem”
Best explanation?