Dictionary WikiDictionary Wiki

Ethics Vocabulary: Moral Philosophy Terms

By the Dictionary Wiki Editorial Team · Published · Updated · 2,058 words · English Language

A close-up image of a hand using a pen to point at text in a book.
Photo by Tima Miroshnichenko

Every serious conversation about right and wrong eventually runs on specialized vocabulary. A physician weighing whether to honor a patient's refusal, a board member asked to sign off on a questionable contract, a student writing a paper on Kant — each needs precise words to think clearly about obligation, consequence, and character. This guide gathers the core terms used across moral philosophy, from the ancient Greeks through hospital ethics committees, corporate compliance offices, and the newest debates around algorithms and climate policy.

Table of Contents

1. The Building Blocks of Ethics

Before tackling competing theories, it helps to pin down the words that all of them share. These baseline ideas sit underneath any further discussion of right conduct, responsibility, and judgment.

Ethics — The philosophical study of how people ought to act, what counts as a good life, and how we justify calling some conduct right and other conduct wrong.
Morality — The actual code of right and wrong a person or community lives by, shaped by tradition, faith, upbringing, reasoning, or some blend of the four.
Values — The priorities a person or culture treats as worth pursuing or protecting — honesty, family, freedom, achievement — and that quietly steer everyday choices.
Moral agent — A being with enough reason and freedom to weigh options and be fairly held accountable for what they choose. Children are gradually treated as moral agents as they develop.
Conscience — The inner voice that nudges us before an action and rebukes or reassures us afterward, regardless of whether anyone else is watching.

With these words in hand, the rest of ethics becomes easier to follow: competing theories argue over which of them matter most, and why.

2. Metaethics: Questions Behind the Questions

Metaethics steps back from everyday disputes and asks what is really going on when we call an act "wrong." Is there a moral reality to discover, or are we simply voicing reactions?

Metaethics — The part of ethics that investigates the status of moral claims themselves: their meaning, their truth conditions, and whether moral knowledge is possible at all.
Moral realism — The position that some moral claims are objectively true, independent of what any culture or individual happens to believe about them.
Moral relativism — The view that right and wrong shift with the framework — cultural, historical, or personal — in which the judgment gets made.
Moral nihilism — The stance that no action is genuinely right or wrong, and that moral talk points at nothing real in the world.
Emotivism — The theory that ethical statements do not describe facts but voice approval or disapproval, so "cruelty is evil" functions more like "boo, cruelty."

Metaethical debates rarely settle overnight, but they decide whether the arguments in later sections are even playing on solid ground.

3. Systems for Judging Right and Wrong

Normative ethics is where philosophers roll up their sleeves and try to spell out what we should actually do. The terms below recur across almost every theory you will meet.

Normative ethics — The effort to build defensible standards for conduct, producing frameworks that tell us which actions merit praise, blame, permission, or prohibition.
Moral duty (obligation) — What you are morally required to do even when it cuts against your preferences — returning a lost wallet, paying a debt, keeping a hard promise.
Rights — Protected claims individuals can make on others — to free speech, bodily integrity, fair treatment — which generate corresponding duties not to violate them.
Justice — Giving each person what they are owed, whether that involves fair shares, fair procedures, or fair responses to wrongdoing.
The Golden Rule — The old instruction to treat others the way you would want to be treated, echoed in Confucian, Jewish, Christian, Hindu, and Muslim traditions alike.

These terms do the heavy lifting in countless debates, from courtroom arguments over sentencing to dinner-table quarrels about taxes.

4. Virtue Ethics and the Shape of Character

Starting with Aristotle, virtue ethics puts character at the center. The guiding question is not "what rule applies here?" but "what would a good person do?"

Virtue ethics — An approach that grounds morality in the settled habits and traits of a flourishing person, focusing on becoming good rather than on ticking items off a checklist.
Virtue — A stable disposition to feel and act well — patience, honesty, generosity, fairness — developed through practice until it feels like second nature.
Eudaimonia — Often translated as "flourishing" rather than "happiness," this is Aristotle's term for a life that goes well overall because it is lived with excellence.
Golden mean — Aristotle's rule of thumb that most virtues sit between two vices; generosity, for instance, lies between miserliness and reckless spending.
Practical wisdom (phronesis) — The seasoned judgment that picks the right action in a messy particular case, something no universal rule can fully deliver on its own.

Whatever you think of the theory, virtue language remains the natural way to discuss mentors, role models, and the slow work of becoming trustworthy.

5. Deontology: Duty Above Outcome

Deontology, most famously in Kant's version, holds that certain acts are simply forbidden or required even when breaking them would produce better results. Rules carry moral weight on their own.

Deontology — A family of theories that anchor morality in duties and rules: an action is right or wrong because of what kind of act it is, not because of how things happen to turn out.
Categorical imperative — Kant's central test: only act on a principle you could consistently will everyone to follow, and never treat a person as a mere tool for your own ends.
Moral duty — For Kant, a binding requirement flowing from pure practical reason, owed by every rational being no matter their mood, desires, or circumstances.
Autonomy — The capacity to govern oneself by laws one rationally endorses, an idea behind modern notions of informed consent, voting rights, and personal liberty.
Moral absolutism — The claim that certain acts — torturing an innocent person, say — are wrong in every possible circumstance, allowing no excuse or override.

Deontological language shows up whenever people talk about "lines you don't cross," even when they have never heard the word "deontology."

6. Outcomes-Based Ethics: Consequentialism and Utilitarianism

Consequentialists flip deontology on its head: the moral weight of an act lives in what happens next. Utilitarianism — the most prominent branch — measures "what happens next" in terms of well-being.

Consequentialism — The view that actions are judged by their results; a good act is one that, all things considered, leads to a better state of affairs than the available alternatives.
Utilitarianism — The Bentham–Mill tradition that says the right action maximizes overall well-being across everyone affected, weighing each person's welfare equally.
Utility — The currency of consequentialist calculation: pleasure, happiness, preference satisfaction, or some richer notion of flourishing, depending on the theorist.
Greatest happiness principle — Mill's formulation that conduct is right insofar as it tends to add to human (and animal) happiness, and wrong insofar as it subtracts from it.
Act vs. rule utilitarianism — Act utilitarians assess each decision on its own consequences; rule utilitarians ask which general rules, if widely followed, would produce the best world.

Cost-benefit analyses, public-health triage, and most talk of "the greater good" borrow their vocabulary from this tradition, whether consciously or not.

7. Ethics in Practice

Applied ethics takes these theories into the field, where abstract principles collide with real patients, clients, deadlines, and regulations.

Ethics and the Environment

Environmental ethics wrestles with humanity's duties toward ecosystems and other species. Deep ecology argues that forests, rivers, and wildlife carry worth in their own right, not just as resources for us. The precautionary principle urges restraint when a new technology or policy might cause serious harm, even if the science is still unsettled — better to slow down than discover the damage too late. Sustainability means using what we need today in ways that leave enough for the people who come after us. Intergenerational justice pushes that idea further, asking what current voters, consumers, and lawmakers owe to grandchildren who cannot yet speak for themselves.

Ethics and Technology

AI ethics — The study of moral questions raised by machine learning and automation: biased training data, opaque decisions, displaced workers, and the limits of handing judgment to software.
Privacy — A person's interest in controlling who sees their body, their data, and their communications, under steady pressure from cameras, trackers, and ever-growing corporate databases.
Digital divide — The gap between those with reliable internet, modern devices, and digital skills and those without, which can quietly widen inequalities in schooling, employment, and health.

Applied ethics is where philosophy stops being a seminar topic and starts showing up in hospital protocols, product roadmaps, and city-hall policy fights.

8. Bioethics and the Medical Frontier

Bioethics grew out of the hard cases medicine and biology keep producing — new technologies, scarce resources, and patients whose wishes deserve respect.

Bioethics — The interdisciplinary study of moral problems in medicine, biology, and biotechnology, drawing on philosophy, law, theology, and clinical experience.
Informed consent — The requirement that a patient genuinely understands a treatment's risks, benefits, and alternatives before agreeing to it, free from coercion or pressure.
Beneficence — The duty to actively promote a patient's welfare, not merely avoid harming them — recommending the therapy most likely to help, for instance.
Non-maleficence — The older "do no harm" principle, reminding clinicians that interventions can injure as well as heal and that risk must be weighed honestly.
Euthanasia — Intentionally ending a life to relieve suffering, a practice where autonomy, compassion, and respect for life pull in different directions depending on the case.

These terms appear daily on hospital ethics committees, inside consent forms, and in legislative fights over end-of-life care.

9. Ethics at Work

Business and professional ethics apply the same concepts to corner offices, construction sites, newsrooms, and law firms. The stakes differ, but the underlying questions rhyme.

Conflict of interest — A situation where a private stake — a friendship, a side income, a family tie — could warp the judgment someone owes to clients, employers, or the public.
Whistleblowing — Going outside normal channels to expose wrongdoing inside an organization, usually at real cost to one's career, reputation, or even safety.
Corporate social responsibility — The idea that a company's duties extend past the balance sheet to include workers' conditions, environmental impact, and the communities it operates in.
Fiduciary duty — A heightened legal and ethical obligation to put another party's interests first, as an attorney does for a client or a trustee does for beneficiaries.

Codes of conduct, licensing rules, and corporate training programs all lean heavily on this small stock of terms.

10. Fresh Problems for an Old Discipline

Plenty of today's moral questions would have baffled Aristotle or Kant. Global justice asks what wealthy countries owe poorer ones on issues like migration, debt relief, and carbon emissions. Animal ethics challenges the default assumption that humans may use other species however they like, scrutinizing slaughterhouses, laboratories, and zoos. Algorithmic fairness focuses on whether hiring software, credit models, and predictive policing tools quietly reproduce the biases baked into their training data. Genetic ethics probes editing tools like CRISPR, asking which changes count as therapy, which cross over into enhancement, and who gets to decide. Social media ethics tackles misinformation, addictive design, and the responsibility platforms bear for what trends on their feeds.

Moral philosophy is, at bottom, a long argument about how humans should treat each other, other creatures, and the world that hosts us. The vocabulary above will not settle any of those arguments, but it gives you the hooks to grab hold of them. Whether you are prepping for an exam, sitting on a review board, or simply trying to explain to a friend why a news story bothers you, precise terms make the difference between a gut reaction and a considered view.

Look Up Any Word Instantly on Dictionary Wiki

Get definitions, pronunciation, etymology, synonyms & examples for 1,200,000+ words.

Search the Dictionary