What makes an action right or wrong?
Each ethical theory answers this question differently. This guide breaks down every theory clearly — with memory tricks, real examples, and side-by-side comparisons — so you can tell them apart at a glance.
Every theory tries to answer: "What is the right thing to do?" They all assume people have free choice, aim to contribute to human well-being, and distinguish moral obligations from personal preferences.
When you face a moral situation, ask: "Am I judging by the principle behind the act? The outcome? The rules we agreed to? My culture? God's commands?" — Your answer tells you which theory you're using.
Quick Comparison Table
| Dimension | Kantianism | Act Util. | Rule Util. | Social Contract | Relativism | Divine Cmd |
|---|---|---|---|---|---|---|
| Key question | Is the principle universalizable? | Does this act produce the most good? | Does this rule produce the most good? | Do rational people agree to this? | Is it accepted by this person/culture? | Does God command it? |
| Focus | Duty & intention | Outcome of act | Outcome of rule | Rights & agreement | Personal/cultural norms | Divine will |
| Consequences matter? | ❌ Never | ✅ Always | ✅ Always | Partially | Depends | ❌ No |
| Universal rules? | ✅ Yes | ❌ Case-by-case | ✅ Yes | ✅ Yes | ❌ No | ✅ Yes (via God) |
| Workable theory? | ✅ Yes | ✅ Yes | ✅ Yes | ✅ Yes | ❌ No | Debated |
| Founded by | Immanuel Kant | Bentham / Mill | Bentham / Mill | Hobbes / Rawls | Various | Theological tradition |
| One-word essence | Duty | Outcome | Rules→Outcome | Agreement | Relative | Obedience |
Kantianism (Deontology)
✅ WorkableKant is the detective who doesn't care about results — only about the rule you
followed. Ask: "Could everyone follow this rule?" If yes → it's
moral. If it collapses on itself → it's wrong.
Keyword: DUTY. UNIVERSALIZE.
RESPECT PERSONS.
Immanuel Kant (1724–1804), a German philosopher who never traveled more than 10 miles from his birthplace — yet became one of the most influential philosophers of the last 300 years. So disciplined that locals set their watches by his daily walk.
Kant believed intelligence, wealth, or talent can be used for evil. The only thing unconditionally good is a good will — a sincere motivation to do the right thing for its own sake, not for reward.
"If an action can be universalized, then the action is right."
Ask: "What if EVERYONE did this?" If the rule destroys itself → it's immoral.
If everyone lied, no one would believe anyone → the act of lying would be pointless → the rule collapses. Therefore, lying is always wrong under Kant.
"I'll skip sorting my trash today." If everyone did this, cities would drown in waste. The rule can't be universalized → wrong.
"Act so that you treat both yourself and other people as ends, and never only as means to an end."
You can't use people as tools for your own goals, even if the outcome benefits you.
Befriending someone only to borrow their car, then ignoring them afterward — treating them as a means (tool) not an end (a person with dignity). Kantianly wrong.
A company hiring applicants without telling them the plant closes in a year. By withholding that info, they're using applicants as tools → treating them as means, not ends → morally wrong.
| Type | Definition | Flexibility | Example |
|---|---|---|---|
| Perfect Duty | Absolute, must always be followed. No exceptions. Usually a "don't do" rule. | None | Never lie. Never murder. |
| Imperfect Duty | Moral obligation with flexibility in when/how to fulfill it. Usually a "do this" rule. | Some | Help others. Develop your talents. |
Perfect = Prohibitions (Don't lie, don't steal) — rigid, no exceptions. Imperfect = Initiatives (Help people, be kind) — you choose when and how. If two perfect duties clash → Kant has no solution (known weakness!).
- Based on logic and reason — rational
- Universal moral guidelines for all people
- Treats everyone as moral equals
- Respects human dignity
- Conflicts between two perfect duties → no solution
- No exceptions, even in extreme cases (e.g. lying to a murderer)
- One action can fit multiple rules — which rules first?
A murderer knocks on your door asking where your friend is (who's hiding in your house). According to Kant, you cannot lie — even to save a life. This is considered a major weakness of Kantianism by critics.
Utilitarianism
✅ WorkableUtilitarians are like spreadsheet lovers. They add up all the happiness (+) and suffering (−) caused by an action, and go with whichever option has the highest score. Keyword: CONSEQUENCES. GREATEST GOOD. CALCULATE.
Founded by Jeremy Bentham and John Stuart Mill. An action is good if it benefits someone, bad if it harms. The focus is entirely on consequences, never on intention or duty.
Happiness = advantage = benefit = good = pleasure. Unhappiness = disadvantage = cost = evil = pain.
Judge each individual action by whether it produces the most good in that specific situation.
You promised to meet a friend, but helping a stranger in an accident would produce more good. Act utilitarianism says: calculate the outcomes — if helping the stranger produces more happiness overall, break the promise.
Building a new highway costs $31M and benefits drivers by $39M. Net gain = $8M. Act utilitarianism says: build it — it's the right action because it produces more good than it costs.
Instead of evaluating each act, identify rules that — if followed by everyone — produce the most good overall. Then follow those rules.
Breaking a promise might produce 1 more unit of good in one case. But the rule "keep your promises" produces far more good society-wide when everyone follows it. So rule utilitarianism says: keep the promise.
Individually, running a red light at 3am might be harmless. But the rule "stop at red lights" produces maximum safety society-wide. Rule utilitarianism says: follow the rule.
Act: "Is THIS action, right now, producing the most good?" (zoomed
in, case-by-case)
Rule: "Would a rule allowing this, if everyone
followed it, produce the most good?" (zoomed out, society-wide)
- Focus on happiness is intuitive
- Practical — most people think this way
- Rule util.: avoids bias ("Is it ok for everyone, not just me?")
- Moral rules survive exceptional situations
- Act util.: can justify breaking promises if numbers work out
- Unclear who to count in the calculation
- Ignores our sense of duty and fairness
- Could justify harming a minority if it helps the majority
Ethical Relativism
❌ Not WorkableThink of moral relativism like fashion trends — what's stylish in one country or decade might be embarrassing in another, and neither is objectively wrong. Keyword: NO ABSOLUTES. CONTEXT DETERMINES MORALITY.
Each individual decides what is right or wrong for themselves. One person can say "X is right," another "X is wrong," and both are correct — for themselves.
Ahmed thinks eating meat is fine. Sara thinks it's morally wrong. Under subjective relativism, both are right — there's no objective standard to settle it.
It makes moral disagreement impossible — you can't tell someone they're wrong, ever. It blurs the line between "I think it's right" and "I want to do it." Not workable as an ethical theory.
Each culture (not individual) determines what is morally right. An action is right if the culture approves it. Because moral judgments differ across cultures, there are no objective moral principles.
In some cultures, arranged marriages are morally normal; in others, they're considered a violation of autonomy. Cultural relativism says neither culture is objectively right or wrong — it just depends on where you are.
It gives tradition more weight than reason. It means you can't criticize harmful practices in other cultures (like historical slavery or genocide) as "wrong" — they were just culturally approved. Not workable.
- Promotes respect for other cultures
- Creates space for equality across societies
- Preserves human cultural diversity
- Fueled by personal/cultural bias
- No basis to criticize harmful practices
- Could justify chaos (no universal wrong)
- Cannot be used as ethical persuasion
Divine Command Theory
⚖️ DebatedThink of it as the ultimate authority figure. God is the author of the moral rulebook (scripture), and morality means following that book. Keyword: GOD'S WILL. FAITH. SCRIPTURE.
The holy books of each religion contain God's directions. Following them = morally good. Violating them = morally bad. This is universal (God's commands apply to everyone) and objective (they don't depend on human opinion).
Stealing is forbidden in major religious texts. A divine command theorist doesn't need to calculate outcomes or ask if a principle can be universalized — the answer is simply: "God forbids it, so it's wrong."
- God is all-good and all-knowing → perfect authority
- Universal rules that apply at all times and places
- Completely objective — doesn't depend on human opinion
- Clear, accessible moral guidance via scripture
- Requires faith in God's existence
- Different religions give different commands
- Hard to apply to non-believers
- Interpretation of scriptures can vary widely
🧠 How to Tell Them Apart
Scenario: A friend asks if their terrible business idea is good. You know it will fail. Do you lie to spare their feelings?
No. "Do not lie" is a perfect duty — it cannot be universalized. Lying treats your friend as a means (to make yourself comfortable), not an end. Always tell the truth.
Depends on the calculation. Does lying produce more happiness (friend feels encouraged) or more suffering (they lose time and money on a bad idea)? Calculate and choose. Outcome determines the answer.
The rule "always give honest feedback to friends" produces better outcomes long-term society-wide (better decisions, better trust). Follow the rule. Probably tell the truth.
Your friend has a right to accurate information to make decisions about their own life (autonomy). Lying violates their right. Rational people in society would agree: don't deceive friends about important matters. Tell the truth.
Whatever you personally feel is right (subjective), or whatever your culture says is polite. Some cultures value blunt honesty; others value saving face. No universal answer.
Most religious traditions forbid lying. If God commands honesty, then telling the truth is the moral choice regardless of feelings or outcomes. Tell the truth.
| If you hear this… | It's probably… |
|---|---|
| "Could everyone do this?" | 🔷 Kantianism (universalizability) |
| "Are you treating them as a person or a tool?" | 🔷 Kantianism (2nd formulation) |
| "What produces the most happiness for the most people?" | 🟠 Utilitarianism |
| "What rule, if everyone followed it, gives the best outcome?" | 🟡 Rule Utilitarianism |
| "What would rational people agree to?" | 🟢 Social Contract |
| "What are your rights? What are their rights?" | 🟢 Social Contract |
| "It depends on your personal values" | 🟣 Subjective Relativism |
| "It depends on your culture / tradition" | 🟣 Cultural Relativism |
| "It's what God commands" | 🟤 Divine Command |
Kant = Duty & Universalize | Utility = Maximize Happiness | Rights = Social Contract | Self/Society = Relativism | Divine = God's Command
Social Contract Theory
✅ WorkableImagine society is a club. Everyone who joins implicitly agrees to the club rules. In return, they get protection, rights, and fairness. Ask: "Would rational people agree to this rule?" If yes → it's moral. Keyword: RIGHTS. AGREEMENT. COMMUNITY.
Hobbes: Without rules and enforcement, life would be chaos — people would just fight over resources. So everyone implicitly agrees to a social contract: give up some freedom, gain safety and cooperation.
Rawls: Added the "veil of ignorance" — design society's rules as if you don't know what position you'll be born into. This ensures fairness for everyone, including the least advantaged.
1st: Everyone gets equal basic rights and liberties — as long as they don't interfere with others' same rights.
2nd (Difference Principle): Inequalities are only fair if they benefit the least-advantaged members of society, and if everyone has an equal opportunity to reach those positions.
Wealthy people pay higher taxes. Under Rawls, this is justified if it funds better schools, healthcare, and social safety nets that benefit the least well-off in society.
Negative right: Others must leave you alone (e.g., free speech, right to privacy). Guaranteed by non-interference.
Positive right: Others must actively do something for you (e.g., free education, healthcare). Requires resources.
Bill sells customers' rental data to marketers. SCT asks: Did customers have a right to keep that data private? Did they implicitly give up that right by renting from him? The answer shapes whether Bill acted wrongly.