Moral Realism vs. Anti-Realism
Introduction
Speaker’s goal: Clarify what “moral realism” is, spell out its four component claims, then present John Mackie’s “Argument from Queerness,” a major challenge to moral realism.
Context: Previous lecture encouraged students to question the “reality” of morality; morality seems both like and unlike mathematics or empirical science.
Moral Realism: Four Claims
Moral realism is true iff all four of the following claims are true. If any one fails, moral realism is false.
1. Moral thoughts are representational (cognitive)
Key distinction
Cognitive states: Aim to represent the world; truth–apt (it makes sense to call them true or false).
Examples:
Belief: “Grass is green.”
Knowledge (hypothetical): “Earth is flat.”
Assumption: “My senses have deceived me.”
Non-cognitive states: Primarily motivational; not truth–apt.
Examples:
Desire: “I want to pass this class.”
Wanting to go to the beach.
Approval of donating to charity.
Consequence if claim 1 is true
Thought “Murder is wrong” represents murder as “having the property of wrongness.”
It therefore makes sense to ask whether that thought is true or false.
Consequence if claim 1 is false (non-cognitivism)
Same thought functions only as motivation (e.g., avoid murder), not as representation; truth/falsity talk mis-fires.
2. Indicative moral sentences are representational
Break-down of terms
Indicative sentence: Perfect for making a statement (not asking or commanding).
Indicatives: “Grass is green.” “The sky is blue.” “Water is .”
Non-indicative example: “Is fire hot?” (interrogative).
Moral sentence: Contains a moral term (wrong, right, good, ought, permissible, etc.).
Moral: “I ought to help.” “Murder is wrong.” “Abortion is permissible.”
Non-moral: “The sky is blue.”
The claim: Any sentence that is both indicative and moral represents the world (e.g., “Murder is wrong” represents murder as wrong).
3. Corresponding moral properties exist
Whatever moral thoughts represent, the properties they ascribe really exist.
Thought: “Murder is wrong.” ⇒ Property “wrongness” exists.
Thought: “Abortion is permissible.” ⇒ Property “permissibility” exists.
Thus: Reality includes properties like being wrong, being right, being what one ought to do, etc.
4. At least some moral thoughts are true
Analogy: Truth of moral thoughts is of the same sense as ordinary truths such as
“Water is ”
“Humans are mammals.”
Claim makes no commitment about which particular moral thought is true—only that ≥ 1 moral thought is.
Quick Self-Check
To accept moral realism, you must accept every claim (1–4).
To reject it, reject at least one claim.
Transition to the Challenge: Mackie’s Argument from Queerness
General intuition: If moral realism were correct, moral properties would be extremely strange (“queer”)—so strange we have no good reason to believe they exist.
Queerness = strangeness/unlikeness to any other properties we’re familiar with.
Mackie’s “Argument from Queerness” – Formal Layout
Things we regard as right/wrong, good/bad influence our actions.
(E.g., believing “murder is wrong” tends to make us avoid murder.)Therefore, objective moral values exist only if there are real properties with a special action-guiding power.
(Objective = part of the “fabric of the universe,” existing independently of minds.)If such real properties existed, they would be very different from all other real properties.
(Ordinary properties—solidity, mass, charge—lack intrinsic motivational force.)If they are that different, then either
a) We can explain the connection between these moral properties and natural properties, or
b) We know them via a special faculty of moral perception beyond the five senses.Neither (a) nor (b) is true:
No satisfactory naturalistic explanation links moral and natural properties.
We possess no special moral “sense.”
∴ Conclusion: There are no objective moral values.
Rationale Behind Each Premise
Premise 1: Empirical/psychological observation—moral judgments affect behavior.
Premise 2: To explain how judgments influence, posits action-guiding properties (not merely descriptive).
Premise 3: Action-guiding power makes them categorically unlike solidity, color, charge, etc.
Premise 4: Epistemic dilemma—either (a) tie them to natural properties (explanatory bridge) or (b) invoke new perceptual mechanism.
Premise 5: Mackie’s negative thesis
No bridge account is compelling (natural properties appear motivationally inert).
Introspection & science reveal only the usual five senses; no “moral detector.”
Logical Structure & Validity Check (High-Level)
Mixed use of modus ponens and modus tollens threads premises together.
Speaker walks through chain:
1 & 2 ⇒ conditional about moral properties.
4 & 5 via modus tollens deny antecedent ⇒ deny consequent of 3 ⇒ deny antecedent of 2 ⇒ no objective values.Net result: Deductively valid; success depends solely on premise truth.
Illustrative Examples & Analogies
Solidity Analogy: Property solidity does not by itself motivate you; your desire plus recognition of solidity does.
Ghost Analogy: If supernatural entities existed yet lacked natural ties, we’d need “ghost sense” to know them. (Parallel to moral sense in premise 4b.)
Mathematical Analogy: Truth of is non-empirical but not action-guiding in itself; underlines queerness of moral properties.
Ethical & Philosophical Implications
If Mackie is correct, moral discourse is systematically in error: moral properties don’t exist even though we talk as if they do (an “error theory”).
Undermines claims like “Murder is wrong” as literally false (though still pragmatically useful for motivation/social order).
Challenges realist theories (e.g., Kantianism, utilitarianism when realist, theological ethics) to supply (4a) an explanatory bridge or (4b) a defensible faculty.
Practical Classroom Application
Students must decide:
Which premise(s) of Mackie’s argument (if any) is/are false?
Or concede moral realism fails.
Discussion Board Tasks (per instructor):
Post either a clarifying question or a critique of one premise.
Then either critique a different premise or reply to a peer’s post.
Note: Two critiques must be distinct; early posts more likely to receive instructor feedback.
Key Take-Away Review (Flash-Bullets)
Moral Realism = 4-part package: cognition, representation in language, real moral properties, at least one true moral thought.
Rejecting any part = some brand of moral anti-realism (non-cognitivism, error theory, subjectivism, etc.).
Mackie’s Queerness Argument:
Moral properties would need in-built motivational force ⇒ unprecedented kind of property ⇒ unbelievable without sensory route or natural explanation ⇒ therefore probably non-existent.
Debate hinges on:
Are moral judgments necessarily motivating?
Can naturalistic reduction (e.g., to evolutionary psychology, social contracts, or utility) preserve realism?
Is there indirect evidence of a moral sense (e.g., moral intuition, empathy)?
Study Reminders
Be able to define each of the four claims precisely.
Remember the cognitive vs non-cognitive distinction (§1) and indicative concept (§2).
Replicate Mackie’s 5-premise structure and explain each premise in your own words.
Practice mapping the logical flow—identify modus ponens vs modus tollens steps.
Prepare at least one objection to Mackie (e.g., disputing Premise 3’s “strangeness,” offering a naturalist reduction for 4a, questioning Premise 5’s dismissal of moral perception, etc.).
Mackie’s “Argument from Queerness” – Explained Simply
Imagine someone believes that “right” and “wrong” are real things that exist in the world, just like rocks or trees or numbers. This is called moral realism. John Mackie argues against this idea, saying that if moral realism were true, these “right” and “wrong” things would have to be really, really strange.
Here’s his argument, step-by-step:
What we believe is right or wrong affects our actions.
Example: If you truly believe stealing is wrong, you usually try not to steal. Your belief guides your behavior.
So, if “right” and “wrong” are real things out there in the world, they must have a special power to make us want to do or avoid things.
Think of it this way: If 'wrongness' is a real property of stealing, that 'wrongness' would somehow have to push you away from stealing. It wouldn't just be a description; it would have a built-in 'action-guiding' force.
But if such real “right” or “wrong” qualities existed, they would be incredibly weird and different from anything else we know.
Normal things like the color blue or the heaviness of a rock don't force you to do anything. Your desire to pick up a rock, plus its heaviness, makes you act. The heaviness itself doesn't intrinsically motivate you. But if 'wrongness' forced you away from something, that's a completely different kind of property—one that's unlike mass, color, or temperature, which don't have built-in commands.
If these “right” and “wrong” qualities are that different (that “queer”), then we'd need one of two things to understand them:
a) A clear explanation of how these weird moral qualities connect to normal, natural things (like how chemical properties connect to water, ). Can we explain how 'wrongness' fits into the physical or psychological world?
OR
b) A special “moral sense” or new human ability (beyond sight, hearing, touch, etc.) to feel or see these moral qualities directly, because they're so strange that our normal senses wouldn't pick them up.Neither of those things is true.
a) We don't have a good, simple explanation that connects these supposed moral qualities to natural things in a way that makes sense of their special action-guiding power. They seem disconnected.
b) We don't have an extra 'moral eye' or 'moral ear' or 'moral radar' that lets us directly detect 'wrongness' or 'rightness' in the world. We have feelings about them, but not a direct sense experience of them.
Conclusion: Because we don't have a good explanation for how these