Notes on Helen Frowe’s Defensive Killing
1. Background Assumptions ........................................................................................................... 1
2. Some Basic Concepts for Individual Self-Defense ..................................................................... 2
2.1 Threats .................................................................................................................................. 2
2.2 On-lookers, Bystanders, Direct Threats, Indirect Threats, Causes of Threats ...................... 3
2.3 Justice and Permissibility...................................................................................................... 5
2.4 Liability and Immunity ......................................................................................................... 5
2.5 Necessity and Liability ......................................................................................................... 7
2.6 Proportionality and Liability................................................................................................. 7
2.7 Agent Responsibility and Moral Responsibility ................................................................... 8
2.8 Exploitative and Eliminative Harms ..................................................................................... 8
3. Substantive Claims about Individual Self-Defense .................................................................... 9
3.1 Moral Responsibility............................................................................................................. 9
3.2 Liability and Moral Responsibility ..................................................................................... 10
3.3 Liability and Necessity ....................................................................................................... 11
3.4 Liability and Proportionality............................................................................................... 11
3.5 Liability and Defense of Honor .......................................................................................... 14
3.6 Liability and Defensive Action without Defensive Harm .................................................. 14
3.7 Liability: Other Claims ....................................................................................................... 15
3.9 Permissibility and Wrongdoing .......................................................................................... 16
3.9.1 General ......................................................................................................................... 16
3.9.2 Direct Threats ............................................................................................................... 16
3.9.3 Indirect Threats ............................................................................................................ 16
3.9.4 Bystanders .................................................................................................................... 17
3.10 Permissibility and Necessity (for Lesser-Evil Justification)............................................. 17
3.11 Permissibility, Exploitation, and Elimination ................................................................... 17
3.12 Permissibility and Duties to Bear Costs ........................................................................... 18
3.13 Permissibility and Reasonable Prospect of Success ......................................................... 18
4. Basic Concepts for the Morality of War ................................................................................... 18
5. Substantive Claims about the Morality of War......................................................................... 19
5.1 Claims about Liability of Non-Combatants ........................................................................ 19
5.2 Claims about Immunity of Non-Combatants ...................................................................... 19
5.3 Other Claims ....................................................................................................................... 20
1. Background Assumptions
Methodology:
- HF does not attempt to identify a full moral theory. She focuses on some main moral
principles. (p. 3).
- As you will see, she has a large number (e.g., more than 20) of basic moral principles.
She is skeptical (fn. ? p. ?) that all relevant moral issues can be captured by small number
of basic moral principles. Some, such as myself, hold that theoretical parsimony is an
important general (but not infallible) guide to truth, and are thus skeptical of approaches
that have a large number of basic principles. Of course, there is an important issue about
how one counts basic principles (given that P1 and P2 can be combined to P1&P2).
-
Many of here principles have the form of being necessary, or sufficient, for
permissibility, or for liability. She means to be conclusive principles, and not merely pro
tanto (which can be overridden by other considerations).
Lethal Threats: HF focuses on defense against lethal threats, but she intends her theory to
generalize to non-lethal threats.
2. Some Basic Concepts for Individual Self-Defense
Note: Most of the material clarifies the terms as HF uses them. In some places, however, I
identify my preferred usage when different. I flag this with a PV.
2.1 Threats
Rights-intrusion (PV): the crossing of a boundary protected by rights:
(1) non-autonomous (neither permissible nor impermissible, neither rightful nor wrongful),
(2) rightful (=just) = autonomous but does not wrong the right-holder (e.g., because she is liable
to such intrusions in virtue of wrongdoing )
(3) wrongful (= unjust) = autonomous and wrongs the right-holder (e.g., because the rightholder
is not liable to such intrusions)
Intrusion-harm (PV): harm from a rights-intrusion. Not all harms are intrusion-harms (e.g., the
harm I suffer when I lose a valued watch).
PV Comments: Note that on my account of intrusion (above) whether something is an intrusion
depends on what rights people have (even when subject to proportionality and necessity).
Nonetheless, whether something is an intrusion does not depend on whether it is unjust, just,
permissible, or impermissible. So, it’s not moralized in the strong sense of the term, which HF
seem to use.
Important: HF focuses on empirical threats (which are just or unjust), whereas the approach I
favor focuses on (rights-based) intrusion-harms (which are non-autonomous, just, or unjust). For
HF, the crucial notion is whether one is made worse off in certain empirical ways. For me, the
crucial notion is whether one is made worse off by having one’s rights intruded upon.
Threat (HF; a purely empirical notion) = an action, bodily movement, or presence, that makes
the victim worse off than she would be in the threatener’s absence.
Example: HF holds (p. 41) that, if each of two shipwrecked people will survive if and only if she
is the only person clinging to a piece of driftwood, neither has a claim-right that the other not
cling to it, and they simultaneously cling to it, then each is a threat to the other, even though
neither intrudes upon the rights of the other.
HF (e-mail) allows that the notion of harm may be person-relative: For example, opening a bag
of peanuts bay be a threat to a person with a peanut-allergy, but not to others.
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PV Comments: So, the same action and physical consequences can be a threat when done to A
(worse off) but not to B because B is indifferent or likes the impact? In e-mail, HF says that
being worse off need not (and probably is not) understood in terms of the agent’s preferences. It
might be understood objectively worse off in some sense.
Question: Does this mean that Smith is a (just) threat to me because the woman I am courting
will leave me for him? Or that the new business is a (just) threat to my business? HF declined to
answer, but she typically focuses worsening survival chances.
Two sufficient, but not necessary, tests for establishing that someone is a threat (and not a
bystander or on-looker), p. 45:
- If Victim were not permitted or not able to harm X, X’s presence would reduce the value
of the most valuable courses of defensive action that are morally permissible (and
feasible) for Victim.
o Note that, if Victim has another equally most valuable defensive action, then there
is no reduction in value. P. 35
o PV’s reconstruction to avoid counterfactuals: The value of Victim’s most valuable
course of defensive action that does not involve harming (using?) X is less than
her most valuable course of defensive action that does involve harming (using?)
X.
- X could be morally responsible for his position with respect (= posing a danger) to
Victim.
o PV: It’s not clear what cases this covers that are not covered by the first condition.
Threats are either rightful (just) or wrongful (unjust). Pp. 41, 43.
- Non-autonomous threats against non-liable people are deemed unjust. E-mail.
o PV: This seems to me to be a mistake. Rocks do not wrong people. Nor do infants
or windblown people. Thus, the threats they pose are not unjust (nor just)—
although, of course, they are unfair in some sense. Non-autonomous threats
should be treated separately from wrongful autonomous threats (even if they are
equally liable).
o PV: By “unjust treatment” HF means something different than I do: she means
“not liable to the treatment”
2.2 On-lookers, Bystanders, Direct Threats, Indirect Threats, Causes of Threats
On-looker for Victim: (1) Her actions, movements, and presence do not contribute, and have not
contributed, to a threat to Victim, and (2) neither intentional harming of her, nor harming her as a
side-effect, would avert/mitigate the threat to Victim. P. 31
- On-lookers are not threats, nor means of averting a threat.
Bystander for Victim: (1) Her actions, movements, and presence do not contribute, and have not
contributed, to a threat to Victim, but (2) suitable (intentional) harming of her would
avert/mitigate a threat to Victim (using her as a shield)
- Bystanders are not causally involved in the threat to victim at all, but their presence offers
additional opportunities for averting a threat, compared with their absence. p. 22, 45.
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Direct threat: an action or bodily movement that threatens without any intervening agency by
others.
- This includes non-autonomous threats. Pp. 32, 63-64.
o Friend, whose paralyzed body is used by Villain to beat Victim to death. P. 32
o Innocent person in a falling trolley that will crush kill Victim. P. 38.
o Innocent person whose body will crush and kill Victim. P. 38.
o Innocent person tied to front of trolley, combined physical mass of which will
crush and kill Victim. P. 39
Indirect threat: an action, bodily movement, or presence, that contributes, via the agency of
another, or via an act of nature?, to a threat. P. 2, 22, 32
- Question: Does nature count as an intermediary (e.g., in Trolley case with freak act of
nature setting off the threat)? Suppose that agent voluntarily goes to sleep by one of the
tracks (if relevant, you can assume that she knows that there is a possibility that Nature
will act as follows). Nature then starts an empty trolley down the track towards the five.
Is the single agent an indirect threat to the others? (Here there is no intermediate agency
of people, just Nature.) HF tentatively says yes (e-mail).
- Enablers (PV’s term): help to bring about a threat (e.g., driving the car from which shot
will be fired).
- Obstructers ([my reformulation of HF, p. 22 to avoid problematic subjunctive
conditionals]: pose no direct threat, but they contribute to a threat (via the agency of
another, or of Nature? [as in Runaway Trolley, p. 33]) because their presence reduces the
value to Victim of the most valuable [= least costly] defensive actions available to her
without harming them.
 Example 1, p. 34: Passerby—who will be startled and thereby reveal
presence of Victim—is an obstructer, since her presence reduces the value
of the most valuable defensive actions (i.e., just hiding quietly) available
to Victim without harming Passerby.
 Example 2: Innocent person lying next to tracks of runaway trolley that
will kill Victim, p. 38.
- Indirect cause of a threat: Her current actions, movements, and presence do not pose a
threat (direct or indirect) but her past actions, movements, and presence causally
contributed to a direct threat by another agent to Victim. P. 36.
o Example: Mafia bosses who hires Hitman to kill Victim and can no longer
influence Hitman. P. 36
Cause of a threat = direct threat or indirect cause of a threat. P. 36.
Question: P. 79, bottom, seems to suggest that one can be a direct threat without being a cause of
that threat. Is this because one is a cause of a threat (direct or indirect) only when one is agentresponsible for bringing it about (as opposed to allowing) the threat (which seems implausible)?
There is also some reference to intentionality, but I’m not sure how it’s relevant. Is it because
one is a cause of a threat only if one intentionally brings it about? I’m a bit lost here.
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2.3 Justice and Permissibility
Just (PV strict sense) = wrongs no one.
Just (common sense, PV loose sense) = does not wrong the intrudee under consideration (e.g.,
the person attacked), even though it might wrong someone else (e.g., because it involves using
someone else’s gun without her consent).
- It’s better, I think, to call such intrusions rightful, where this leaves open whether
someone else is wronged.
Just (HF) = does not harm anyone who is not liable to that harm
- Note: Non-autonomous harms can be unjust in this sense.
Permissible (PV, and HF?) = (1) not impersonally wrong, and (2) wrongs no one without
overriding (= lesser evil) justification.
Overriding (lesser evil) justifications: This is a kind of consequentialist appeal (but with special
moral theory of the good) that can override rights considerations. It allows that an action can be
permissible even though it wrongs someone, when the expected value of the impersonal moral
goodness of its consequence is sufficiently greater than that of the best consequences obtainable
without wronging anyone.
- Note that in this case wronging is necessary to achieve the expected benefits.
- Some versions allow such overriding justifications only when there is a conflict of rights.
Others allow them even when there is no conflict of rights.
- This typically requires that the benefit be significantly greater than the wrongful harm
imposed (or, according to HF, harm she has a duty to bear).
o Where a person is liable (or has a duty to bear) to 5 units of harm, it can be
permissible, on the basis of overriding justification, to impose 6 units of harm, for
5 units of benefit, since this is really 1 unit of excess harm for 5 units of benefit.
pp. 10, 84-85
o HF (pp. 9, 69) writes of “discounting” liable harm, but she means (confirmed by
e-mail) “ignoring” that harm. By “morally weighted harm”, she means “non-liable
(and no duty to bear) harm”. She doesn’t mean to invoke weights.
2.4 Liability and Immunity
Liability to harm: Individual lacks a right against having the harm inflicted, because he has
forfeited his usual rights against such harm as a result of behaving in a particular way (e.g., not
because of onset of dementia). He is not wronged by such harm.
- HF adds: Ordinarily, he may not defend himself against such harms. P. 3, 4, 72, 96. Note
that p. 85 (after Apparent Murder) treats the second condition as always holding for
liability.
- PV Comment: I wouldn’t invoke rights of defense in this definition. I think, for example,
that non-autonomous threats are liable to defensive harm (e.g., not owed compensation)
but they have rights of self-defense.
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Question about Dignitary example, pp. 83-84: You say that Dignitary is not liable to defensive
attack, because she hasn’t forfeited her right not to be so attacked (because Dignitary’s defensive
attack is just, despite the false belief). Agreed.
- You then say that she lacks a right not to be suitably attacked, because she has a duty to bear
to bear certain costs in virtue of the threat she imposes. I say: If she has this duty, and she is
not complying with it, does she not forfeit her right not to be suitably attacked?
o PV: I think that HF reserves liability to attack to cases where the individual has lost
her rights against attack in virtue of being a threat for which she is responsible. So,
there will be lots of cases where a person is not wronged by the attack even though
she is not liable.
- Of course, even if you grant this, you may also hold something stronger: By posing the threat
to Victim, she immediately (prior to any opportunity to bear some of the costs and thus prior
to any failure to meet her duty) loses her right not to be suitably attacked. But I don’t
understand why this isn’t a case of forfeiting rights in virtue of posing a threat. Can you
explain why not?
Liability to defensive harm: liability to harm that serves a defensive purpose (e.g., reduces unjust
harm). P. 100
Liability to non-defensive harm from defensive action: liability to harm that the defending agents
believes serves a defensive purpose but in fact serves no defensive purpose
- Example: In Apparent Murder, p. 85, Enemy is morally responsible for making Victim
falsely believe that Enemy poses an unjust lethal threat. HF says that he is liable to being
killed, even though this is not defensive harm.
HF does not distinguish between formal and effective liability (my terms), but I believe that the
distinction is sometime relevant for her discussions.
Formal liability to a certain intrusion (PV; McMahan calls this potential liability): The intrusion
is compatible with absolute proportionality (which is an upper limit, based solely on the
consequences of the attacker’s past and present and possible future actions in the absence of any
defensive action).
- Facts about the consequences of defensive attack (how effective the defense is, whether it
is necessary, the harms suffered by various people, etc.) are not relevant.
Effective liability to a certain intrusion (PV): The intrusion does not wrong the individual, given
the full circumstances and the consequences of defensive action.
- Pure proportionality externalists [PV’s term] (e.g., purely past-regarding externalists)
about liability hold the formal liability is all there is to (full) effective liability.
- HF’s proportionate means externalism holds that facts about whether the defense has
reasonable prospects of success (e.g., is a means) are relevant.
- Internalists hold that necessity is also required.
Immunity from harm: not permissible to harm (even if liable).
- PV: This terminology is somewhat confusing. On a Hohfeldian analysis of rights, an
immunity to X is simply the lack of a liability to X. Better to say: impermissible to harm.
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2.5 Necessity and Liability
Necessity condition for liability (roughly): the least costly means to harmed person of achieving a
relevant goal (e.g., reduction in harm from non-rightful threats) without imposing costs on nonliable others.
Internalists (such as McMahan and PV) hold that that liability involves a necessity condition, but
externalists (such as HF) deny that it does.
2.6 Proportionality and Liability
Proportionality
- Narrow: This is a condition on liability to harm.
o It is typically held that the harms to which a person is liable must not be too great
relative to the achieved reduction in the non-rightful harms (e.g., killing someone
to stop him from stealing your chocolate bar is narrowly disproportionate). –
 Normally, however, they may be significantly greater than the benefits
obtained (e.g., kill a wrongful attacker to stop him from cutting off your
legs).
- Wide: This is a condition for overriding (i.e., lesser evil) justifications for permissibility.
o The harms to non-liable parties must not be too great relative to the achieved
benefit from the reduction in the non-rightful harms.
 Normally, these harms (in excess of any harm to which the bearers are
liable) must be significantly less than the benefits obtained (e.g., one may
kill one innocent person to save a million, but not to save one).
Important: HF (fn. 38, p. 155; e-mail) uses “proportionality” to mean something like the kind of
standards usually used for “narrow proportionality”, but she applies those standards both to cases
where the individual is potentially liable and to cases where the individual is not potentially
liable. She says that wide proportionality is simply part (along with necessity and reasonable
prospective of success) of a lesser-evil justification for wronging some people. I’m not sure,
however, that she is consistent.
The following are some distinctions that I would make, that HF does not make.
Absolute proportionality (PV): the upper limit of harm that can be effectively proportionate,
based solely on the consequences of the attacker’s past and present and possible future actions in
the absence of any defensive action).
- Facts about the consequences of defensive attack (how effective the defense is, whether it
is necessary, the harms suffered by various people, etc.) are not relevant.
Full proportionality (PV): proportionality in a given circumstances given the facts about the
attacker’s past, present, and possible future actions, and given the facts about options the
defender has and their consequences. For example, if a defensive action imposes a massive, but
absolutely proportionate, harm on an attacker with only a trivial reduction in the intrusion-harms
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imposed by attacker, then the defensive action may not be fully proportionate, even though it is
absolutely proportionate.
2.7 Agent Responsibility and Moral Responsibility
Agent-responsibility (often confusingly called “moral responsibility”, but not by HF): whether a
person’s presence or movements, and the associated results “belongs” to an agent, or “flows
from” her agency (e.g., not the movement of an insane or windblown person.). P. 74
Moral responsibility (PV) = some positive degree of (moral) culpability = agent-responsibility
for acting wrongly (impermissibly) [e.g., based on degree of psychologically autonomous choice,
strength of the evidence that action was wrong, and resistibility of choice]
Moral Innocence (PV): no agent-responsibility for acting wrongly (impermissibly) [even if
acting wrongly]
Moral responsibility for an unjust threat (HF): agent-responsibility for acting unjustly (or
perhaps for acting wrongly)
On the other hand, she seems to distinguish two cases based on motives.
- Minimally responsible: only slight degree of moral responsibility?
- Culpable: high degree of moral responsibility? But she writes:
o agent acts unjustly from bad motives (e.g., greed, jealously, or malice; p. 1;
Deliberate Trolley, p. 34). [Are bad motives really needed if one freely and
knowingly acts wrongly (but perhaps indifferently)?]
o Why do motives matter for culpability? Why isn’t it enough that one freely and
knowingly acts wrongly (but perhaps with good motives)? Aren’t I culpable when
I wrongly take your wallet, in order to help some starving children? Here we
assume that the ends do not justify the means.
- Moderate responsibility (a possibility confirmed by e-mail): something in between (for
example, someone under minor duress knowingly acts wrongly)
Morally innocent (HF): not morally responsible for acting wrongly (or unjustly)
- agentially innocent: not agent-responsible for any threat that is unjust (or
impermissible?). P. 74
o non-threats
o threats who are not agent-responsible for the threat: (e.g., fetuses, schizophrenics,
falling people; p. 8, 10, 21, 22, 25)
- agentially responsible for threat that is unjust (impermissible?) but not morally
responsible (e.g., because there was inadequate evidence that her action was
impermissible or inadequate opportunity to avoid performing it).
2.8 Exploitative and Eliminative Harms
Note that the following are defined in terms of the agent’s aims (intentions). Related definitions
could be given in terms of (1) the agent’s beliefs, (2) evidentially supported propositions, and (3)
the objective facts.
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Eliminative harming: harming that aims at mitigating/eliminating a threat that she currently
poses (and thus not deriving any benefit from her current presence). P. 8 [e.g., killing the falling
person who will otherwise crush one]
Exploitative (sometimes called opportunistic) harming: harming that aims at making use of
Victim to mitigate/eliminate a threat to which she does not currently contribute and (added by email) for which she is not causally responsible in virtue of past actions (movements or presence)
(and thus deriving a benefit from Victim’s current presence and from her overall presence). (p. 8)
[e.g., pulling a bystander in front of one to block Aggressor’s bullet that would otherwise kill
one]
Merely (or barely) opportunistic harming (killing) [e-mail: a third, non-overlapping category]:
harming in a way that uses [ignore references to “aims to use”] the victim to avert a threat for
which she (or her body) is causally responsible in virtue of past actions (movements or
presence), but to which she (her actions, movements, or presence) does not currently contribute
(and thus deriving a benefit from Victim’s current presence but not from her overall presence)
[e.g., killing the person who threw the knife to ringleader, where ringleader now is attempting to
kill one with it, so that the rest of the mob will be scared away]. P. 163.
To use a person= To use solely as a means [sometimes abbreviated to: to use a means] = To use
their person (in the more generic sense) exploitatively p. 46.
- E-mail: Eliminative use is not using as a means, but merely opportunistic use is.
3. Substantive Claims about Individual Self-Defense
All views are HF’s, unless otherwise noted.
3.1 Moral Responsibility
An agent is morally responsible (for an unjust threat) if and only if (confirmed in e-mail) Agent
intentionally fails to avail herself of a reasonable opportunity to avoid imposing the unjust threat.
p. 10, 73
An agent intentionally fails to avail herself of a reasonable opportunity to avoid unjust threat, if
and only if (confirmed in e-mail) [my reformulation] (1) she believes, or reasonably believes,
that she has a feasible action that (a) is not too costly to her or other innocent people and (b) will
not pose the unjust threat, and (2) she chooses an action that she correctly believes will lead to an
unjust threat. p. 11
- Unlike McMahan, HF denies that (e.g., in Careful Motorist) mere knowledge that one
imposes a very small risk of imposing unjust harm is sufficient to make one morally
responsible for that harm, if it eventuates. Risks that are sufficiently low (relative to the
risked harms) are deemed irrelevant (because one can reasonably believe that one won’t
impose the harm).
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-
-
-
If, however, one knows that one is contributing to a project that aims at (intends) unjust
intrusion-harm (e.g., Driver in Drive-By), then one may be morally responsible for intrusionharm, even if the risk is very small. P. 82
The threshold for a reasonable belief that the threat one poses is just is very high. P. 184.
o Those who knowingly contribute to a threat are morally responsible for their
contribution unless (1) they have very strong evidence that the threat they contribute
is just, or (2) they have a reasonable belief that they lack a reasonable opportunity to
avoid posing the threat. P. 184.
The standards for reasonable belief above are sensitive to the same factors below for being
too costly.
Whether an action is too costly depends on: (1) the cost to the agent, and other innocents, of
avoiding posing the unjust threat, (2) the unjust harm, if any, to the victim of posing the unjust
threat, and (3) the kind of threat (direct threat, indirect threat, indirect cause of a threat), if any,
that the agent poses, and (4) whether the agent will be allowing herself to threaten, or causing
(bringing about) herself to threaten (if she threatens at all).
- The limit on costs depends on the circumstances.
o Lowest limit on cost: for indirect threats who allow themselves to threaten.
o Highest limit on cost: for direct threats who cause themselves to threaten.
o High, but lower, limit on cost: for indirect cause of threat. P. 74
- An action is not unreasonably costly for an agent if it does not exceed the cost that she is
morally required to bear for Victim’s sake. P. 86
3.2 Liability and Moral Responsibility
Narrow View of Liability (HF’s and McMahan’s [original?] view): A person can be liable to be
defensively harmed only to avert a threat for which she is morally responsible. P. 17, 188
Broad View of Liability (Hurka’s and PV’s view): A person can be liable to be defensively
harmed to avert any proportionate threat (even ones for which she is not morally responsible;
e.g., threats from others).
Moral responsibility for an unjust (direct or indirect) threat renders a person liable to defensive
force/harm. P. 10, 27, 72, 80.
- Driver who, under threat of death from Terrorist, drives car for a drive-by killing is liable to
being defensively killed.
A person can be liable to being defensively harmed only to avert an unjust (direct or indirect)
threat for which she is morally responsible (but it can be permissible, a lesser evil justification)
to harm a non-liable person. pp. 4, 37, 73, 75, 83
- Harming a person to avert a threat for which she is not responsible makes exploitative use of
her, and therefore wrongs her (because no one is liable to such use), even if she is liable to
defensive harm (to reduce unjust harms for which she is responsible). P. 188
So, non-autonomous threats and reasonably ignorant unjust threats are not liable to defensive
attack, are wronged if so attacked, and are owed compensation if so attacked? I would reject this.
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HF (e-mail) says that that they have certain duties to avoid harming and are not wronged if they
fail to perform those duties. She also says that they are not owed compensation when defensively
attacked. Seems a bit confusing.
Thus, a person can be liable to being defensively harmed if and only if the harm helps averts an
unjust threat for which she is morally responsible.
3.3 Liability and Necessity
Internalism about liability (e.g., McMahan, PV): (Effective) Liability requires necessity
Externalism about liability (Quong and Firth, HF): Liability does not require necessity.
- Purely backward-looking externalism about liability (Quong and Firth?): Liability is based
solely on what the agent has done in the past (and not what the options and consequences are
for defending against her).
o There is no requirement that the harm be necessary or a means (instrumental) to
advancing the relevant goal (e.g., reduction in unjust harm).
- Pure proportionality externalism (PV): Liability is based solely on proportionality (which
can be sensitive to what the agent is currently doing and may do in the future).
o There is no condition how effective, or necessary, the defensive action is.
o In e-mail, HF acknowledges that this may be a better description of the Quong and
Firth position. There is no reason to limit the relevant facts to past behavior.
- Proportionate means externalism about liability (HF): An agent is liable to a given harm only
if it is a proportionate means of averting a threat. This requires both proportionality based on
the past and some positive effect on averting the threat (a means). P. 12-13
In middle of last paragraph of p. 105, HF adds: “attacker must be morally responsible for an
unjust threat”. This is part of her account of proportionality, but it seems best not to build it into
the content of proportionate means externalism (so that it is a more general doctrine).
Harms that had some prospect of averting a threat but failed to do so fail the necessity test. P.
152
PV: This seems quite wrong. The various tests should be based on the objective facts at the time
of action. If the objective facts are probabilistic, the relevant tests (necessity, proportionality)
should be based on the objectively expected value at the time of action. How things happen to
turn out is irrelevant. (Defensive action that is 99.99% likely to succeed but doesn’t can still be a
means and can be necessary and proportionate.)
3.4 Liability and Proportionality
Proportionality is judged by the magnitude of the harm to which one contributes, not by the
magnitude of one’s contribution to that harm (pp. 76-78), nor by the cost of taking a reasonable
opportunity to avoid the harm).
- HF’s argument on p. 78 for the first point on assumes that those who jointly (via joint plans)
impose a threat are liable for only their contribution to the threat (with contributions
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summing to 100%), but I think that in such cases, each individual can be fully liable for the
threat (summing to more than 100%). Joint intentions change things morally, I think.
Proportionality of defensive harms is determined by whether, if fully successful, the harm to the
attacker is proportionate to the reduction in harm to defender (and perhaps others). P. 150-51
PV’s view: Absolute proportionality is (in agreement with HF) not based on the probability of
successful defense. It is merely the most harm that can be imposed in light of the threat imposed.
Full proportionality (in a given choice situation, given the facts about the consequences of
various choices) is based on the (objectively) expected values: of the harm imposed on the
attacker and on the level of non-rightful harm imposed on the defender. I disagree with HF that
(full) proportionality is based on the appropriate balance, if the defense if fully successful.
Imposing 10 units of intrusion-harm to prevent, with certainty, an unjust imposition of 10 units
of intrusion-harm may not wrong an innocent attacker, but imposing the same harm may wrong
her if it has only a 1% chance of success.
Foreseen harms (e.g., to others) that are mediated by other agents are heavily discounted in a
defender’s proportionality calculation (e.g., a victim preventing her attack even though it will
lead attacker to attack two additional women).
PV: For (narrow) proportionality, the question is the limits of harm to an intruder that will not
wrong her. A natural thought is that the intruder must not suffer harms that are too great relative
to the protection to defender of the defense. Shooting a rapist in the leg to stop a rape is narrowly
proportionate in this sense, even if it has the result that the rapist will rape two additional women
(whom he would not otherwise have raped). It does not, it seems to me, wrong the rapist (even
though it may be wrong) to shoot him in the leg where this stops the rape. HF seems to assume
that the effects on everyone must be determined to determine narrow proportionality, and that
makes it seem in places (e.g., p. 129) that she is invoking wide proportionality. She isn’t, but she
is, I claim, invoking an implausible criterion for narrow proportionality It’s enough, I say, for
the intrusion-harm to the attacker not to be too great relative to the protection to just the
defending agent (independently of the effects on others, although those effects may be relevant
to the permissibility of so defending).
PV: More generally, my view is that narrow proportionality is satisfied as long as there is some
group of individuals (including the defending agent or not) who have authorized, or at least not
denied authorization, relative to whom the defense is proportionate. That’s enough to establish
that the attacker is not wronged (where necessary for the achieved reduction in non-rightful
intrusion-harms). That leaves open whether the defense is permissible (and the effects on
everyone are relevant for that).
[We now return to HF’s views]
At some point [if it defends enough innocent victims], it’s going to become proportionate to start
inflicting even lethal collateral harm as part of a bid to prevent the unjust, forcible imposition of
this regime. End of first full paragraph, p. 141.
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It can be proportionate to risk collateral damage to innocent people in the course of averting
harm to the lesser interests of sufficiently many people. (p. 14).
Whereas one ought to bear lethal costs rather than (intentionally?) cause oneself to nondefensively kill an innocent person, one need not bear lethal costs rather than (intentionally?)
allowing oneself to non-defensively kill an innocent person. Nonetheless, one must bear
significant costs (e.g., paralysis rather than death) in the latter case, since one is morally
responsible for being a threat (since the opportunity to avoid being a threat is reasonable and one
intentionally chooses not to take it). Indeed, one is liable to having such costs imposed. P. 79.
A person who is morally responsible for indirect lethal threats (e.g., intentionally obstructing
escape route) is liable to defensive force, including being killed. P. 10
PV: General note on killing: I think, rather controversially, that full proportionality for nonrightful killing is based on the actual setback to interests the killing imposes on the victim and
on the actual setback to interests that defensive action will impose on the attacker. If the killer
will in any case die in five minutes (or have a comparably low quality longer life), she may be
liable to being killed to protect your little finger. If you will die in five minutes (or have a
comparably low quality longer life), a non-autonomous killer (for example) with a normal life
may be not be liable to being killed to stop her from killing you. HF seems to assume that all
innocent lives are equally valuable for proportionality calculations.
A note on PV’s views on proportionality in case they are relevant to discussion: I distinguish (in
the concepts section) between absolute formal proportionality (given only the facts about the
attacker’s past and possible future actions) and full proportionality (given the full facts, including
the defender’s feasible options and their consequences). Full proportionality, I claim, requires
aggregative proportionality in its consequences (comparing the benefits and costs for feasible
actions to defender and attacker). This requires that the attacker not suffer more intrusion-harm
than under the most intrusion-harm he experience by an absolutely proportionate (for everyone)
defensive action that minimizes the total (for defender and all intruders) excess intrusion-harm.
Excess intrusion-harm for an individual is the intrusion-harm to her in excess of the level of
intrusion-harm for which she would be agent-responsible for imposing on defender (and which is
in fact non-rightful) in the absence of defensive action (adjusted upward, if culpable).
- For example (with just one intruder), suppose that imposing intrusion-harm of 10 on nonautonomous intruder is absolutely proportionate to avoid intrusion-harm of 10 to defender
(e.g., it doesn’t wrong intruder when the only alternative is for defender to bear a harm of 10
herself). The intruder is thus formally liable to having 10 units of harm imposed.
Nonetheless, he may not be effectively liable to this, because it may be aggregatively
disproportionate. Suppose that the defender has one additional option, which imposes 2 units
of intrusion-harm on intruder and reduces her intrusion-harm to 1 (from 10). That option
minimizes total excess intrusion-harm (2+1 =3, vs. 10) and intruder only suffers 2 units of
intrusion-harm. Thus imposing 10 units on intruder imposes more harm on intruder that the
excess intrusion-harm minimizing action. It is fully (but not absolutely) disproportionate
because it is not aggregatively proportionate.
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3.5 Liability and Defense of Honor
A person’s honor (PV’s reconstruction) is the public recognition of her being an entity with
certain rights (who thus can be wronged). The more rights (in the superset sense) that are
publically recognized, the greater her honor. Her honor is reduced when she is wronged, but less
so when she, or others, forcibly resist such wronging, and (I would add) less so, when such
wronging is publically recognized, condemned, and/or rectified.
HF (e-mail) suggests that she should have used the term moral standing (and perhaps would not
invoke any of the public recognition stuff I suggested above).
Unjust threats to the victim’s honor are liable to defensive attack to protect that honor (even if
the defense does not reduce the physical threat). Pp. 13, 90, 101. Fn. 32, p. 179
Question: Why not simply allow that harms need not be physical harms? Surely psychological
harms are relevant. Do you think that, even if the victim’s interests/wellbeing is in no way
affected, that her honor still can be affected (e.g., because it’s a matter of public recognition and
that matters, even the victim doesn’t care about it)?
Question: Are physically harmless wrongings threats to the victim’s honor? HF (e-mail) says
that spitting and pulling hair are threats to honor, although I say that these are not harmless.
Question: Is it only (or primarily?) culpable primary threats that threaten one’s honor (and not
unjust threats based on mistaken belief that that was permissible?). p. 110. Fn. 23 suggests this.
Yes, HF confirms.
Question: I wonder whether even innocent autonomous unjust threats do not threaten one’s
honor, if they are not be publically recognized as mistakes.
Although proportionality in defense of one’s honor is sensitive to the seriousness of the primary
threat, it is not (pace Statman) proportionate to impose a harm equal to the primary harm merely
to defend one’s honor, when this has no effect on the primary harm one suffers. It is, for
example, proportionate to break a wrist or arm to defend one’s honor against rape but not to
impose blindness, paralysis, or death. Pp. 112-13, Fn. 32, p. 179
3.6 Liability and Defensive Action without Defensive Harm
Threats can be liable to harms imposed by defensive action (even if it does not reduce the risk of
harmful threat), even if they are not liable defensive harms P. 100, 154
- Example: In Apparent Murderer, p. 86, Enemy is morally responsible for the Victim’s false
belief that his (ineffective) attack was needed to defend against an unjust attack by Enemy.
Enemy is liable to be killed by Victim.
o Note: Liability is, I believe, attacker-relative. Enemy may be liable to be killed by
Victim in this case, but he is not liable to being killed by a third-part who knows that
Enemy poses no threat to Victim.
- Other examples?
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Question: How are the conditions for liability to non-defensive harm different from those for
liability to defensive harm? What are the general conditions for liability to harm, or to nondefensive harm?
- HF replies: That’s something I need to think more about. My thought in the book was that
one needn’t be responsible for an unjust threat to be liable to non-defensive harm, but only
morally responsible for Victim’s belief that one poses an unjust threat. But Kim Ferzan has
pointed out that, if liability is instrumental, Enemy can’t be liable in these cases, since
harming him averts no threat. So I need to revise my treatment of these cases.
Defensive attacks in response to unjust attack are unjust, if they have no prospect of success (and
hence the harms imposed are not defensive harms). Proportionality is irrelevant. Such attacks are
not means to defense and thus neither proportionate nor disproportionate. P. 151.
- They also fail the necessity (last resort) requirement for permissibility.
Question: Why are there no standards of proportionality, even if they are different? For example,
suppose in Apparent Murder the merely apparent threat is a slight bruise instead of death. Is
Enemy still liable to be killed (non-defensively)? HF: Yes, this (and the next question) is part of
what needs re-thinking
Question: I thought that one could be liable to defensive attack even if it serves no defensive
purpose (e.g., where one is responsible for the attacker’s belief that she is being unjustly attacked
by you). HF: I need to rethink this.
3.7 Liability: Other Claims
It wrongs a person to be used solely as a means (i.e., exploitatively).
Agents are liable to have defensive harm inflicted on them, when they have a duty to bear such
harm.
Victor Tadros also makes the stronger, and much more controversial, claim that agents are liable
to have defensive harm inflicted on them, when they would have a duty to bear such harm, if they
were able to. I am deeply suspicious of this appeal to a counterfactual duty. Various things may
need to change for the person to be able, and that might fundamentally alter the situation. I think
it better to simply specify the relevant actual conditions that make people liable. HF doesn’t
endorse the counterfactual duty.
3.8 Liability and Rectification
In general, HF gives little attention to rights of rectification for past wrongings (e.g., recognition,
apology, compensation). I believe that failure to fulfill the rectification duties imposes an
intrusion-harm and that this provides the basis for using harmful force (subject to the same
conditions as all defensive force). There is a current threat in my sense: the threat of infringing
these rectification rights.
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3.9 Permissibility and Wrongdoing
3.9.1 General
Lethal defense of lesser interests can be permissible (on the basis of an overriding justification)
when enough people are protected (i.e., with aggregation). P. 14
To wrongly risk harm to a person is a wrong independent of whether the harm is realized. P. 156.
It is impermissible to inflict collateral harms on innocents in defense of honor. Fn. 32, p. 179
It is impermissible to inflict harm on someone (even if liable to it), if that harm serves no moral
purpose (e.g., for reducing primary unjust harm or for reducing threat to one’s honor). P. 117,
Agents who pose (directly or indirectly) an unjust (e.g., lethal) threat, but who are not morally
responsible for the threat (e.g., because their evidence supports the view that there is no
reasonable opportunity to avoid so acting) have a duty to avoid [to the extent possible, I would
add] imposing the unjust (e.g., lethal) harm (e.g., even if the costs are lethal)—even though they
are not liable to defensive harm (e-mail). P. 9, 67
3.9.2 Direct Threats
It is permissible to kill one innocent direct threat to save one innocent person. P. 40
Question: How is this possible? If they are innocent, they are not morally responsible. If they are
not morally responsible, they are not liable. If they are not liable, then it is not permissible to kill
them to save one innocent life. HF: They have a duty to bear significant harm to avoid killing an
innocent person. This means that inflicting that much harm upon them does not wrong them
(they’re not liable but they nonetheless lack rights against suffering the harm). PV: What if they
are unable to avoid killing the innocent person? They have no duty in this case. I guess she
means something like: Those who have a duty, when possible, to bear a significant harm are not
wronged (or at least: it’s not wrong) when that harm is imposed on them.
3.9.3 Indirect Threats
An indirect threat is liable defensive force only if she is morally responsible for her contribution
to that threat. Pp. 47, 72. [In the text, HF writes: It is permissible to use defensive force against
an indirect threat only if she is morally responsible for her contribution to that threat, but she
retracted this by e-mail. It can be permissible on the basis of an overriding justification.]
It is nearly always impermissible to kill innocent indirect threats merely to save a single life. P.
10
- It is impermissible to kill one innocent lying at the side of the tracks” [i.e., an innocent
obstructer] top of P. 40.
- It can be permissible, however, to kill one innocent person to save millions of lives.
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-
It is permissible to divert the trolley from where it will likely kill ten to where it will likely
kill one, but it is impermissible to divert a trolley from where it will likely kill two to where it
will likely kill one. (Moreover: The standard is set even higher in cases where one
intentionally (rather than merely foreseeably) harms an innocent person.) P. 154
3.9.4 Bystanders
There is a “prohibition on killing innocent bystander in the course of saving [only] one’s own
life”. p. 6.
The constraints on harming innocent indirect threats and innocent bystanders are sufficiently
stringent that they can be overridden only by harms that meet both a proportionality standard
(since they can be liable) and a lesser-evil standard. It’s proportionate to kill an innocent indirect
threat or bystander to save just two innocent people, but the lesser-evil standard requires more. It
requires, for example, that there is a reasonable prospect of achieving a proportionate good that
significantly outweighs the harm inflicted on the non-liable persons.
Revised Defense Account of mediated harms (endorsed by HF, p. 14):
- Foreseen but unintended mediated (by other agents) harms are relevant to the
permissibility of defensive action, but they are heavily discounted for the proportionality
requirement.
- The duty of agents to bear costs, rather than trigger merely foreseen mediated harms to
others, is limited to her (general) duty to rescue others from (unjust?) harm.
3.10 Permissibility and Necessity (for Lesser-Evil Justification)
A defensive harm, against a given person, counts as necessary (e.g., for permissibility) if it averts
[added by e-mail: in a least costly manner] a the threat that she poses, even if other people will
then go on to impose the harm averted. P. 208
Because harms to innocent people who are not potentially beneficiaries of the action are morally
weighted moral heavily than harms to innocent people who are potentially beneficiaries of the
action, where the harms are the same for the two groups, necessity (for permissibility) requires,
when possible, harming the potential beneficiaries is required by the necessity condition (since
only it minimizes moralized harm). (Thus, a state may be required to impose such harm on its
own innocent non-combatants rather on innocent non-combatants in the aggressor state.) P. 146.
PV: Note that here HF appeals to a moralized notion of necessity, with moral weights for costs
and benefits.
3.11 Permissibility, Exploitation, and Elimination
Compared with eliminative killing of liable people, there is no higher burden of justification for
merely opportunistic killing (=opportunistic killing for which they are morally responsible in
virtue of past actions, but not in virtue of present actions, behavior, or presence) P. 179, 181, 193
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Killing a person exploitatively (e.g., killing Roof Shooter, p. 189, to block the bullets from Better
Shooter, when it is costly to avoid Roof Shooter’s bullets) wrongs her, but it is a much less
serious wronging when she is liable to eliminative killing (as Roof Shooter is on an internalist
account, in which there is no necessity condition) compared to when she is not. Thus, it is easier
for such actions to be permissible on the basis on a lesser-evil justification. P. 193
3.12 Permissibility and Duties to Bear Costs
It worse for a person to suffer a given physical harm as the result of a rights-violation (even if a
non-autonomous?) than to suffer the same physical harm as the result of a natural cause. P. 136.
Question: Is this also true of permissible rights infringements? HF: I need to think more about
this.
- Thus (?), in defense cases, Victim is required to bear roughly the same cost to prevent
mediated harms to others as he would be to rescue others from comparable harms. P. 136.
3.13 Permissibility and Reasonable Prospect of Success
The Subsuming Account of Reasonable Prospects (Hurka and McMahan; rejected by HF): The
permissibility of defensive action (individual, or for jus ad bellum) does not have an independent
requirement of reasonable prospects of success (in achieving reduction in wrongful intrusionharms). This is because, they claim, it is automatically covered by the requirement that the
intrusion-harm imposed be narrowly proportionate (if the chance of success is too low, the
expected benefits will not be high enough)
- HF claims that narrow proportionality is not sensitive to probability success. Instead, it is
based on the assumption that defensive action succeeds in preventing (completely?) nonrightful intrusion-harm. P. 15. Stated otherwise, I think: Proportionality is based solely on
the risk of non-rightful intrusion-harm that the other agent risks imposing, and not on the
success of any defensive action. (This is true of what I call formal proportionality, but
not, on my view, of effective proportionality.)
- HF claims that, if there is no prospect of success, then the intrusion-harm is unnecessary.
(p. 14). Agreed.
- HF claims that the reasonable prospect of success requirement (for individual selfdefense as well?) is a distinct requirement for lesser evil justifications and it requires that
there be a reasonable prospect of success that the use of force will be a means (i.e.
increase the chance) of achieving a proportionate end. P. 15.
The requirement of a reasonable prospect of success is a lesser-evil constraint on the infliction of
proportionate harms. It provides protection against collateral harm to innocents. P. 153.
4. Basic Concepts for the Morality of War
Reductive individualism (endorsed by McMahan, HF, and PV): Moral rules of war are just the
moral rules of everyday life. (p. 2). No special permissions and no special constraints.
Non-Combatant Immunity (traditionally accepted, rejected by HF and PV): It is impermissible to
intentionally target non-combatants in war. P. 164.
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Vital interests are those interest that warrant lethal defense even to protect those interests of a
single person (i.e., without aggregation).
Lesser interests are those interests that do not warrant lethal defense to protect those interests of
a single person.
Conditional force: Aggression that will become violent only if resisted. P. 124
Purely political aggression: Aggression that, if not resisted, threatens only political interests
(e.g., sovereignty or territorial integrity) and not any vital interests of individuals (life, physical
harm, etc.).
5. Substantive Claims about the Morality of War
5.1 Claims about Liability of Non-Combatants
Contributions to welfare goods (food, medicine) can make one liable just as much as
contributions to military goods (weapons) can, when one is morally responsible for the
contribution to an unjust threat. P. 204.
- Those who knowingly finance (e.g., by paying taxes) unjust war can be liable to
defensive attack. P. 212.
Many/most non-combatants in Western democracies are morally responsible for their
contribution to the war effort, and are thus liable to defensive attack, because (1) they knowingly
contribute to the war effort (e.g. providing taxes, food, or military equipment), (2) they not have
very strong evidence that the threat to which they contribute is just, and (3) they do not have a
reasonable belief that they lack a reasonable opportunity to avoid posing the threat. Pp. 15-16,
184.
In war, past contributions to macro-threats one’s state imposes (its war effort) count as current
threats for the individual. Thus, individuals with such past contributions can be liable (when
morally responsible for those contribution) for current defensive harm. P. 194-95.
Red Cross medics can be liable to being defensively killed, if they are (as they often are) morally
responsible for indirect unjust lethal threat (e.g., by saving the life of an unjust soldier who will
return to battle). P. 202.
- It is permissible for them to treat unjust soldiers who will return to battle only if the just
combatants consent to this. P. 205.
5.2 Claims about Immunity of Non-Combatants
It can be permissible (on the basis of a lesser evil justification) to kill non-liable non-combatants,
even medical personnel. P. 17
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The requirement of necessity, for permissible defensive force, provides only limited protection to
non-combatants. P. 188
Given (1) the epistemic difficulty of identifying liable non-combatants, and especially (2) the
difficulty of attacking liable non-combatants without causing impermissible collateral harms
(e.g., to young children), there is in practice a strong presumption that attacking non-combatants
is impermissible (but which can be overridden in specific cases). 188.
5.3 Other Claims
Reasonable prospects of success is an independent jus ad bellum requirement of permissibility
(not reducible to the narrow proportionality requirement): See above under individual selfdefense.
Conditional Force Argument (rejected by HF): If the political interests of individuals are not
vital, harmful forcible resistance to purely political aggression is (narrowly?) disproportionate.
- This lends some support to non-reductive statism (e.g., because the sovereignty of the
state is vital to the state).
HF’s response to Conditional Force Argument: It can be proportionate to risk collateral damage
to innocent people in the course of averting harm to the lesser interests of sufficiently many
people. (p. 14).
Defense against merely political aggression that is only conditionally violent can be permissible,
because foreseen, but mediated (by other agents), harms are heavily discounted in a defenders
proportionality calculation. P. 137.
If there is a duty of care (as claimed by Rodin), it is owed to all people (equally?) and not merely
(or primarily) to one’s co-citizens. P. 138.
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