Can You Know Right from Wrong Without a Reason?

That Gut Feeling: When You Just Know Something Is Wrong

You see a classmate swipe another kid’s lunch. Before you can explain why, you feel a tug in your chest: that’s not okay. It happens fast, like a flash of color, not like a math proof. Some philosophers have argued this flash is a real way of knowing — a kind of moral vision. They are called intuitionists, and they claim we can grasp some moral truths without any argument at all.

For the 18th-century thinker Richard Price (1723–1791), this flash is an intellectual seeming. Just as your eyes can make the world look red or round, your mind can make a proposition seem true — “hurting someone innocent is wrong” might present itself to your mind the way a bright green leaf presents itself to your eyes. It isn’t a belief yet; you might still doubt it later. But the seeming itself is immediate, not reasoned out.

Price carefully distinguished this from ordinary feelings. A feeling is just your mind sensing its own state, like hunger. An intellectual seeming, by contrast, points outward to something real about the world. When you “see” that an act is wrong, you’re not just reporting a twinge inside you — you’re glimpsing a moral fact. That’s why he called intuition the “immediate apprehension by the understanding.” It’s a kind of mental grip on a truth that needs no further proof.

Bright Truths That Light Themselves

Intuitionists say some moral propositions are self-evident. That doesn’t mean they are obvious to everyone. It means the proposition carries its own evidence — understanding it can be enough to justifiably believe it. You don’t need an argument from something else; the truth stands on its own legs. Many famous intuitionists, like W. D. Ross (1877–1971) and G. E. Moore (1873–1958), maintained that basic ethical claims work this way.

But how can you tell a merely apparent self-evident truth from a genuine one? The philosopher Henry Sidgwick (1838–1900) proposed a checklist: a genuine self-evident proposition must be clear and distinct, survive careful reflection, fit with other self-evident truths, and attract wide agreement. If you think you’ve found a moral “axiom” but thoughtful, well-educated people in different times and places keep disagreeing, maybe it isn’t so self-evident after all.

This brings us to one of the biggest challenges. Disagreement is everywhere. People argue about whether it’s okay to eat meat, to lie to protect someone’s feelings, or to punish criminals severely. If moral truths were really self-evident, wouldn’t all reasonable people eventually agree? Intuitionists respond that much disagreement is really about non-moral facts — like whether lobsters feel pain — or about the weight of competing considerations. Two people might agree that causing pain counts against an action, but disagree about whether the pain is strong enough to outweigh other goods. Ross himself held that only prima facie duties — like the fact that harming someone counts against an act — are self-evident, while our final all-things-considered judgment rarely is.

Trolleys and Trapdoors: When Your Moral Compass Spins

What if your moral gut feelings can be twisted by completely irrelevant things, like the order in which you hear a story? That’s what some modern psychologists claim. Consider three famous thought experiments. Switch: a runaway trolley will kill five people unless you pull a lever to divert it onto a track where it will kill one. Most people say flip the switch. Bridge: you can stop the trolley only by pushing a large man off a footbridge; most people say that’s wrong. Trap door: you open a trap door to drop the man onto the track — suddenly many more people say it’s permissible, even though you’re still using him as a means.

This is puzzling, because the reasoning behind the different reactions seems hard to defend. Some researchers argue our judgments are swayed by physical contact or personal force — factors that shouldn’t matter morally. Even framing effects appear: if people read the bridge case first, they become less likely to approve the switch case. If the wording shifts from “killing” to “saving,” answers change. These results, pushed by philosophers like Walter Sinnott-Armstrong, suggest that many moral intuitions are unreliable.

But Ross’s version of intuitionism might slip past this problem. He never claimed our overall verdicts are self-evident. What is self-evident, he argued, is only that certain features have a moral pull: that saving lives counts in favor of an act, that killing counts against it. These prima facie glances don’t seem to wobble with different presentations — you probably still feel that killing someone is a moral minus in all three trolley scenarios, even if you’re unsure what you should do overall. The debate over whether empirical psychology really threatens moral intuition hinges, then, on what exactly intuitionists claim we intuit.

What Do We Mean by “Good”? The Impossible Definition

So far we’ve looked at knowledge. But intuitionists also say something bold about the world: moral properties like goodness and rightness are non-natural. They can’t be boiled down to physical or psychological facts. G. E. Moore gave this idea its most famous weapon, the open question argument. Try to define “good” purely in scientific terms, say “good = causes pleasure.” Now ask: “This act causes pleasure, but is it good?” Moore pointed out that the question feels open — it’s not like asking “Is a widow a married woman?” which betrays confusion. The openness suggests that goodness isn’t simply the same thing as any bundle of natural facts.

Moore’s argument has a lot of kick, but critics pushed back. Maybe a true definition could be non-obvious, just like “a mammal is a species where females suckle their young” was a discovery, not a tautology. Moreover, distinguishing moral concepts from moral properties matters. Even if our concept of good can’t be replaced by natural concepts, it might still turn out that the property goodness just is some natural property, just as the property heat turned out to be mean kinetic energy despite our ordinary concept of hotness being quite different.

Still, intuitionists like Moore and later A. C. Ewing (1889–1975) insisted that moral facts are a special kind, not detectable by scientific instruments. As Moore later put it, a natural property is one studied by the natural sciences and psychology — redness, pleasure, brain states. Moral properties, he claimed, aren’t like that. You can’t find wrongness under a microscope.

The Spooky Side of Morality: Why It Bugs People

If moral properties aren’t physical or psychological, what are they? Many philosophers call them “queer.” John Mackie (1917–1981) argued that non-natural moral facts would be utterly unlike anything else we know. They would supposedly be intrinsically motivational — just seeing that an act is good would push you to do it, a power no other property has. Mackie thought that’s too strange. Plus, if moral properties lack causal powers, how could we ever detect them? Our eyes see colors because light strikes our retinas. But a property that doesn’t cause anything couldn’t leave a trace in our minds — or so the worry goes.

Intuitionists have replies. Some, following Ewing, analyze goodness in terms of reasons: to be good is to have properties that give us reason to approve of the thing. If you come to see that a stray cat’s suffering gives you reason to help, it’s not mysterious that you then want to help. The so-called magnetism of the good becomes the ordinary pull of a reason recognized by a rational creature. The epistemic worry — how can we know causally impotent facts? — might be answered by noticing that plenty of things we know about (like numbers or logical laws) don’t push on us physically either, yet we manage to grasp them.

But the deepest unease remains. If moral truths are more like math than like measles, why do we disagree so bitterly about them? And if evolution planted our moral sentiments just to keep groups cooperating, maybe those “bright truths” are really just useful illusions. That’s why the intuitionist’s claim is still so alive. It touches everything from how we argue at the dinner table to how we build laws. When you feel certain that bullying is wrong, you’re taking a stand in a centuries-long conversation about whether that certainty is a glimpse of something real — or just a feeling dressed up as a fact.

Think about it

1. If everyone in your school agreed that a particular harmful joke was acceptable, would that make it morally okay? What would you say to someone who thinks a behavior is wrong only if most people say so?
2. Can you imagine a world where causing innocent pain is genuinely good? If you can’t, is that because your imagination is limited, or because the wrongness of such pain is self-evident?
3. When a strong sense of unfairness rises in you, how would you try to figure out whether it’s a reliable moral insight or just a gut reaction shaped by your upbringing?