Transplant Case

Formulation of the Thought Experiment

The Transplant Case is a widely discussed thought experiment in contemporary moral philosophy and bioethics, designed to probe whether it can be morally permissible to kill one innocent person to save several others. Versions of the case appear in the work of Judith Jarvis Thomson and other late 20th‑century analytic ethicists.

A canonical formulation runs as follows: A brilliant surgeon has five patients, each of whom will soon die without a different vital organ (heart, lungs, kidneys, and so on). A healthy stranger comes in for a routine check‑up. The stranger is a perfect donor match for all five patients. If the surgeon were to kill this healthy individual and distribute the organs, all five critically ill patients would live. If the surgeon does nothing unusual, the healthy person will live, and the five others will die.

The scenario is usually “idealized” to remove practical complications: there will be no bad side effects such as loss of public trust, the killing can be done painlessly and secretly, and the surgeon can be certain of success. Under these conditions, purely outcome‑based reasoning suggests that sacrificing one to save five maximizes overall lives saved.

Nevertheless, many people judge that it would be morally impermissible for the surgeon to kill the healthy person. The tension between the apparently better outcome (more lives saved) and the strong moral intuition against killing is the core of the Transplant Case.

Philosophical Significance

The Transplant Case is primarily deployed to challenge simple act utilitarianism, which holds that the morally right action is the one that maximizes overall utility (often interpreted as happiness, welfare, or lives saved). If only the number of lives saved mattered, then killing the healthy stranger would be not merely permissible but morally required.

The common intuition that such killing is wrong appears to reveal deontological constraints—moral rules that prohibit certain actions (such as intentionally killing an innocent person) even when violating them would produce better aggregate outcomes. In this sense, the Transplant Case supports the idea that:

• Persons have strong rights not to be used merely as means to others’ ends.
• There is a fundamental moral distinction between killing and letting die.
• Morality may involve agent‑centered restrictions, limiting what each agent may do, irrespective of overall benefits.

The case is often discussed in parallel with trolley‑type problems. In the classic trolley scenario, many are more willing to divert a runaway trolley to a track where it will kill one instead of five, yet they typically reject killing a healthy person for organs. Comparing these cases has been used to explore the moral relevance of factors such as:

• Intention versus foresight (whether the harm is intended as a means or merely foreseen as a side effect),
• Physical agency and contact (turning a switch versus cutting up a patient),
• Personal rights and bodily integrity,
• The structure of threats (redirecting an existing threat versus creating a new one).

Thus, the Transplant Case sits at the intersection of theoretical ethics and applied medical ethics, illuminating debates about organ donation, triage, and the ethics of life‑saving interventions.

Major Responses and Criticisms

Philosophers and ethicists have offered a range of responses to the Transplant Case, often using it to refine or test broader moral theories.

1. Utilitarian and consequentialist responses

Some act utilitarians accept the implication that the surgeon ought to kill the one to save the five, holding that moral theory sometimes conflicts with common intuitions, which may be unreliable or prejudice‑laden. Others appeal to rule utilitarianism, arguing that we should follow rules (such as “Do not kill innocent patients”) whose general acceptance produces the best consequences. On this view, even if the one‑off killing would have better immediate results, it violates a rule whose social adoption maximizes welfare.

However, the thought experiment is often stipulated to exclude real‑world consequences like mistrust of doctors, forcing rule utilitarians and more sophisticated consequentialists to consider whether there are intrinsic, non‑contingent drawbacks to such killings (for example, erosion of security or respect for persons) that still count as worse consequences.

2. Deontological constraints and rights‑based theories

Deontological and rights‑based theorists use the Transplant Case to defend strong moral side‑constraints. According to these approaches, individuals have stringent rights not to be killed or used as mere means, and these rights cannot easily be outweighed by aggregate benefits. The surgeon’s duty not to intentionally kill an innocent patient blocks the apparently beneficial outcome.

Some appeal to Kantian ethics, emphasizing that using a person solely as a means (harvesting organs without consent) fails to treat them as an end in themselves. Others draw a sharp line between doing harm and allowing harm, arguing that actively killing the healthy person is morally worse than passively allowing the five to die of their pre‑existing conditions.

3. The Doctrine of Double Effect and intention

Another influential response invokes the Doctrine of Double Effect (DDE), a principle that distinguishes between harm intended as a means to an end and harm merely foreseen as a side effect. In Transplant, the healthy person’s death is a means to saving the five: without their death, the organs cannot be obtained. Thus, on DDE, the surgeon’s action is impermissible.

Proponents contrast this with certain trolley‑type cases where the death of one is not intended as a means but is a foreseen side effect of diverting harm. Critics question whether the intention/foresight distinction is psychologically or morally robust enough to ground such different judgments.

4. Personal identity, numbers, and aggregation

Some theorists argue that the case illustrates difficulties with straightforward aggregation of persons’ interests. While saving five is “better” in an impersonal sense, doing so by violating one person’s right to bodily integrity may be incompatible with viewing each person as a separate, inviolable center of value. Others note that the case dramatizes the moral weight (if any) of numbers: can more people’s needs simply outweigh the rights of the fewer?

5. Practical and empirical critiques

From a more applied perspective, critics contend that the scenario is too unrealistic to guide real‑world medical ethics. In practice, informed consent, professional norms, and legal frameworks rule out non‑consensual organ harvesting. Empirical work in moral psychology also examines how people actually respond to such cases, exploring whether strong “don’t kill” intuitions arise from evolved heuristics, social learning, or rational reflection.

Despite these reservations, the Transplant Case remains a central tool for clarifying and testing moral theories. It continues to shape debates about killing versus letting die, rights versus overall welfare, and the limits of using individuals as means to social or medical ends.