Table 1.

Four principles of medical ethics

Principle	Working definition16	Link to older ethical theories
Autonomy	Obligation to respect the decision-making capacities of persons	Deontology (rule based) or duty; example: Immanuel Kant said, ‘Act in such a way that you always treat humanity, whether in your own person or in the person of any other, never simply as a means, but always at the same time as an end’
Beneficence	Obligation to provide benefits and to balance benefits against risks	Utilitarian (outcome based); example: maximise the good for the greatest number of people
Non-maleficence	Obligation to avoid causing harm	Opposite of benefit; example: primum non nocere
Justice	Obligation of fairness in the distribution of benefits and risks	Fairness (social justice) (e.g. John Rawls's A Theory of Justice); example: try to maximise the interests of the worst off