What Is Applied Ethics? Definition & Key Branches

Question

What is applied ethics, and why has it become the fastest-growing area of moral philosophy? The answer is that applied ethics is where philosophy meets the real world — where the theories about right and wrong are tested against the concrete problems of medicine, business, technology, and public life.

Quick Answer

Applied ethics is the branch of moral philosophy that applies ethical theories to concrete moral problems. Where theoretical ethics asks the abstract question "what makes an action right or wrong?", applied ethics asks the practical question "what should be done here?" — in this hospital, this company, this algorithm, this ecosystem. Its major branches are bioethics and medical ethics (life, death, and health care), business ethics (commerce and the corporation), AI and technology ethics (algorithms, data, and automation), environmental ethics (nature and the climate), and animal ethics (the treatment of non-human beings). Its method is the movement between theory and case: the general principle — "act so that you treat humanity always as an end, never merely as a means" — is brought to the particular situation, and the particular situation in turn tests and refines the principle. Applied ethics emerged as a distinct discipline in the 1960s and 1970s, driven by the civil rights movement, the Vietnam War, and the new technologies of medicine, and it is now where most professional philosophers work.

Historical Wisdom

Applied ethics has ancient roots and modern flowering. The ancients practiced it: Aristotle analyzed the ethics of the polis, and the medical ethics of the Hippocratic tradition is two and a half millennia old. But the modern field was born in the 1960s and 1970s, when the civil rights movement, the war in Vietnam, and the explosion of medical technology — ventilators, organ transplants, genetic research — forced moral philosophers out of the seminar room and into the clinic, the courtroom, and the newsroom. Philippa Foot's introduction of the trolley problem in 1967, Peter Singer's "Famine, Affluence, and Morality" in 1972, and the founding of the journal Philosophy & Public Affairs in 1971 mark the birth of the modern discipline. What had been a tradition of marginal cases became a professional field with its own journals, chairs, and controversies.

Philosophical Perspectives

Applied ethics is not a separate ethics but the application of the existing theories. The three great traditions each bring their method: deontology asks what duties and rights are at stake, and whether the action could be willed as universal law; utilitarianism calculates the consequences, asking which option produces the greatest balance of well-being over harm; virtue ethics asks what the person of good character would do, and what the action says about the agent. The applied ethicist does not choose one theory in advance: the case is examined from all three angles, and the theories are tested against the intuitions the case provokes.

The method of applied ethics is the movement between principle and case, and it works in both directions. From theory to case: the principle is brought to the situation, and the situation is judged by the principle. From case to theory: the hard case — the trolley problem, the violinist in Singer's argument, the doctrine of double effect — exposes the tensions in the principle, and the theory is refined in response. This is why the trolley problem has been so productive: it is a case designed to separate the theories, to show where deontology and consequentialism disagree.

Lessons From Thinkers

From Philippa Foot: the hard case is the test — her trolley problem showed that our moral intuitions distinguish doing and allowing, intending and foreseeing. From Peter Singer: the argument must follow the consequences wherever they lead — "famine, affluence, and morality" showed that the comfortable have obligations to the distant poor. From the tradition: applied ethics is the proof of the philosophy — the theory that cannot guide action is the theory that has failed.

Practical Application

Applied ethics has a concrete method for the person facing a real moral problem. First, describe the case: what are the facts, the options, and the consequences? Second, run the three examinations: what duties and rights are at stake (deontology)? What are the consequences for everyone affected (utilitarianism)? What would the person of good character do (virtue ethics)? Third, test the intuitions: which option feels right, and why? Fourth, decide and act, taking responsibility. The method is the daily practice of the applied ethicist, and it is available to anyone facing a hard moral decision — in medicine, in business, in technology, in the ordinary life.

Quotes

The definition of the field is stated in the tradition: "Applied ethics is the application of moral philosophy to real-world problems." Philippa Foot states the method of the hard case: "The trolley problem is designed to show that our moral intuitions are more complex than our theories." And the justification of the field: "A moral theory that cannot guide action is a theory that has failed."

Related Questions

• What Is Medical Ethics? — the bioethics branch.
• What Is AI Ethics? — the technology branch.
• What Is Business Ethics? — the commerce branch.
• What Is the Trolley Problem? — the field's most famous case.