Natural Sciences: Ethics
Knowledge Stakeholders
Ethical in the natural sciences depends on which role you play. The TOK concept of the distinguishes at least three groups:
- Pure scientists — produce new knowledge
- Applied scientists and technologists — translate knowledge into technologies and interventions
- Users — employ those technologies in practice (doctors prescribing, patients taking, engineers deploying)
Each group bears different responsibilities. A pure physicist who establishes the principles of nuclear fission is not the same person as the engineer who builds a reactor — and both are different from the government that decides to use the technology. Responsibility does not vanish by being passed down the chain; it is distributed.
Ethical Constraints on Methods
Two moral principles, in permanent tension, underlie most scientific codes of conduct:
: some actions are absolutely forbidden because they treat persons as mere instruments. Human beings — and some other animals — are autonomous agents with their own interests. Experimenting on a person without their knowledge or against their will violates this principle regardless of the potential benefit.
: an action is ethical if it maximises overall good. A degree of suffering may be acceptable if the benefits outweigh it. This is the principle that permits dentistry, and also clinical trials — provided consent is given.
Neither principle is sufficient alone. Most ethical codes combine them: absolute prohibitions (do not X) alongside conditional permissions (Y may be acceptable if benefits outweigh harms and consent is given). The requirement for — that subjects freely agree to participate with full understanding of what is involved — sits at the intersection of both principles.
The Nuremberg Code (1947)
Nazi scientists conducted brutal experiments on concentration camp prisoners during World War II. The Nuremberg Trials (1945–49) prosecuted 23 doctors; 16 were convicted. In response, the Nuremberg Code was drafted — the first formal ethical code for research on human subjects. Its first and most fundamental principle:
“The voluntary consent of the human subject is absolutely essential.”
Consent must be freely given, informed, and ongoing; the subject may withdraw at any time. The Nuremberg Code established that no scientific goal — however valuable — can justify the use of a person as an unwilling experimental subject.
The Declaration of Helsinki (World Medical Association, first adopted 1964, revised 2022) built on this foundation: “The health of my patient will be my first consideration.” Research aims must never override subjects’ rights and interests.
Epistemic Harm
Not all ethical harm in science is physical. is harm to the quality of knowledge — and it can cascade into physical harm when flawed knowledge is applied.
The Wakefield case is a clear example: Andrew Wakefield published a paper in 1998 claiming a causal link between the MMR vaccine and autism, without adequate evidence. The resulting drop in vaccination rates contributed to measles outbreaks — physical harm traceable to an epistemic failure.
is the set of norms that guard against epistemic harm. It requires:
- Honesty in collecting, analysing, and reporting data
- Transparency about methods, limitations, and conflicts of interest
- Proper attribution of sources and co-authors’ contributions
- Resistance to pressure from funding bodies to exaggerate positive results or suppress negative ones
s — the dispositions that make a scientist a reliable producer of good knowledge — include honesty, carefulness, objectivity, openness, and accountability.
Constraints on What to Investigate
Ethics enters science before an experiment begins: choosing what to investigate is itself an ethical decision.
Some topics are arguably off-limits — an investigation designed to maximise civilian casualties from a weapon violates the Kantian principle with no offsetting benefit. Others are off-limits for different reasons: gathering racial data in a criminal investigation may be both ethically wrong and epistemically irrelevant.
There is also an ethics of omission: failing to investigate something you should investigate. Scientists and institutions may bear responsibility for not studying the harmful effects of a process — early radiation researchers, including possibly Marie Curie herself, are plausible examples. In new fields, caution is warranted precisely because we do not yet know what we do not know.
Responsibilities in Application
Much of the practical ethical debate about science concerns its applications. Animal testing — rats, dogs, primates — is routine in pharmaceutical and cosmetics development. The TOK question is whether Kantian concerns about the suffering of autonomous creatures are outweighed by the utilitarian benefits. It is generally easier to make this case for medicines than for cosmetics.
What gets investigated is also shaped by commercial viability. Rare diseases (“orphan diseases”) may attract little research investment because the market is too small to recoup development costs — even when the human need is acute. The tension between commercial sustainability and human need is a genuine ethical dilemma with no easy resolution.
The Thalidomide disaster (1950s–60s) illustrates the opposite failure: a drug approved without adequate animal testing caused severe birth defects in thousands of children. The ethical lesson is not that animal testing is always wrong but that insufficient testing is an ethical failure as much as a scientific one.
The User’s Responsibility
Users of scientific technologies bear responsibilities too. The distribution of responsibility between producer and end user depends on whether the user has sufficient knowledge to use the product safely. A patient who ignores clear safety instructions cannot hold the producer responsible. This creates an obligation on users to be informed — and on producers to communicate clearly.
Case Study: Oppenheimer and Rotblat
J. Robert Oppenheimer led the Manhattan Project, which produced the atomic bombs dropped on Hiroshima and Nagasaki in 1945, killing over 200,000 people. Physicist Joseph Rotblat resigned from the project when Germany’s defeat made the original justification (preventing Hitler from getting the bomb first) obsolete.
Both responses — staying and leaving — engage the question of where responsibility lies along the knowledge-stakeholder chain. In TOK terms, the Los Alamos team were appliers of pure knowledge (nuclear fission theory was already established); their role was engineering and application, not fundamental discovery.
Oppenheimer later became an advocate for nuclear disarmament and opposed the hydrogen bomb. His famous quotation after the Trinity test — “Now I am become Death, the destroyer of worlds” — shows he understood the weight of the knowledge he had helped apply.
The Oppenheimer/Rotblat contrast is one of the clearest examples in the history of science of two knowers facing the same ethical situation and reaching different conclusions about their responsibilities.