Even ethical theories that see individual rights and especially liberty rights as the strongest
possible moral claims– as trumps vis-à-vis other moral considerations such as the common
good– will necessarily acknowledge limits to those rights. If people use their freedom to
harm others or otherwise impose their will on another person, then the freedom of the aggressor is undermining the freedom of others. Any liberal framework that endorses
freedom or autonomy as an important value will therefore accept that someone’s freedom
must be curtailed if this is necessary to protect the freedom of other persons. Ideally every individual enjoys maximum freedom that is still consistent with the equal liberties of her fellow citizens. According to John Stuart Mill (1859: 22) the only purpose for which
someone’s freedom can be constrained is to protect other individuals. One should not
compel persons to act in specific ways for their own good, but it is justified to limit their freedom in order to prevent evil to third parties. This idea is normally referred to as the harm principle:
HP1: It is justified to restrict the liberty of person A in order to prevent A from causing harm
to person B.2
Moreover, according to Mill, this is the only justification of liberty-limiting actions and
policies. Even the strongest libertarian will agree with liberty-limiting interventions that
protect against harm, and HP1 is therefore relatively uncontroversial. Moreover, the
application of the principle to protection against the harms of infection may seem rather straightforward. The principle and its application however do raise important questions.
First, the concept of ‘causing harm’ is not as clear as one might hope – certainly not in
relation to the harmful nature of contagion. Second, the harm principle as understood in
HP1 can be given a very strong justification as it is in a sense a necessary condition to
freedom as such, but this is a rather narrow interpretation of Mill’s harm principle.
Although HP1may apply to certain measures of infectious diseases control, many forms
of infection (hence policies to prevent infection) fall outside the scope of HP1. Many
authors in fact endorse a broader interpretation of the harm principle, but such an
expanded principle HP2(see below) may require other sources of justification.
‘Causing harm’
A paradigmatic case of harm, where the harm principle would obviously apply, is one where someone deliberately intends to infect another with a dangerous disease. A recent example is the Groningen case in the Netherlands. In 2007, three people in Groningen were arrested
because they had injected others with HIV-infected blood. The culprits– all HIV seroposi-
tive themselves– contacted their victims through internet chat boxes, and invited them to
homosexual sex parties at home. During these meetings they first intoxicated their victims, and then administered intravenous injections with HIV-infected blood. They also injected blood in each other’s veins, ‘just for the kick’ as they confessed after their arrest.
Although persons with HIV can be treated relatively well (at least in high income countries), the infection does severely undermine their health. Adequate medical treatment involves a complex regimen of drugs that negatively affect their quality of life. A deliberate and malevolent act to infect someone else with HIV is a clear case of harm. State interven- tions to prevent such harms and to punish evildoers are justified on the basis of the harm principle.
The Groningen case may be a paradigmatic case of inflicting harm, but it is not a paradigm case of infectious disease control. Public health measures to control contagious diseases do not focus on active malevolent behaviour, but on more common means of infection. For example, even though persons may be aware that they are a carrier of a virus or other infectious agent, they may simply forget to take precautions, or otherwise act
negligently and spread disease. The story of‘Typhoid Mary’ Mallon is a case in point. At
some point she was told she carried a disease that could be easily transmitted if she worked in a kitchen, but she decided to take up her job after all, hence infecting more persons. As discussed before, public health measures that demand people isolate themselves, or refrain from certain activities, or otherwise take precautions, may be detrimental to their own well- being, and this may well motivate them to be non-compliant or negligent. The reason why such measures as compulsory isolation are used is because such behaviour, even though
2 It is not necessary for the principle that B is a specific person. It could be a non-assignable member of
normally not malevolent, can be dangerous to others. If there is a clear risk that infected persons will harm others, even though the harm is caused by negligent rather than malevolent behaviour, then the harm principle may justify compulsory measures.
So far we have focused on cases where people have negligently or malevolently imposed risk on others. Again, these cases cover only part of all current possibilities for compulsory measures. Infectious diseases may spread where no one is yet aware of the infection. A disease could have an incubation period where an asymptomatic person is already infectious. Or persons may have certain symptoms, but not realize that they are infectious.
Many policies– including compulsory measures – aim to prevent spread of disease in such
contexts: mandatory screening at borders, routine HIV-tests for pregnant persons in risk groups, prohibition of mass events, closing of schools, etc. Can the concept of harm and the scope of the harm principle be stretched much further, and justify such measures as well? It is often assumed in public health law and ethics that the principle can be as broad as this (Gostin, 2003). Yet this depends partly on how the principle and its core concept, harm, are understood.
Is it correct to assume that Sally, who does not know she is a hepatitis B carrier, and who has unprotected sex with Richard, is causing harm to Richard? Is Henry causing harm to his colleagues if he goes to work, unaware that he is a vector for a new and dangerous influenza virus? Paul got very ill and was admitted to a hospital, and now it appears that he has SARS and that he infected two nurses who cared for him. Did Paul harm the nurses?
Maybe Sally is causing harm if we assume that she and Richard should have taken precautions against sexually transmitted diseases anyway. If that is true, this may reveal that ‘harming others’ and even ‘causing harm’ are normative concepts, that only apply when
certain moral norms are transgressed.3Joel Feinberg (1984: 36) indeed defines harm as a
wrongful setback to the interests of another person, where‘wrongful’ refers to transgression
of a moral norm (Feinberg,4: 36). Certainly Henry can not be considered as harming his
colleagues, if harm would involve the transgression of a moral norm: he just goes to work
and is perfectly justified in doing so. Paul did not‘do’ anything, and even though actually
his admittance to the hospital did appear to be a threat, there is no sense in whichPaul
could have been responsible for it. This seems to imply that, if we emphasize the moral
nature of causing harm, HP1only justifies compulsory measures towards persons who are
in some sense responsible for the harm that they produce.5 Compulsory policies towards
persons who are unaware that they pose a threat to the health of others might not be justified on this interpretation of the harm principle.
3 The example may provoke the reaction that Richard can not be said to have been harmed if he
agreed to having unprotected sex (volenti non fit injuria), but this only affirms the claim that harm is a moral concept.
4 However, Feinberg is specifically focusing on the role of the harm principle in the context of criminal
law, and this may be a reason for thinking that the relevance of his concept of harm in the context of infectious disease control is limited.
5 Note that this is not just a result of the definition of harm as such, but also in our understanding of
someone causingharm. Did Henry cause harm to his colleagues, or was the harm caused by the virus? Statements of causal responsibility may seem purely empirical, but when they concern actions or omissions of persons, they will inevitably involve evaluative statements that presuppose some background of norms (Yoder, 2002).