Just as seeing a tree gives you reason to believe it’s there, sensing that a stranger is creepy gives you reason to walk away

by Marc A Moffett  BIO

At the Campidoglio, Rome, 1984. Photo by Richard Kalvar/Magnum

is professor of philosophy at University of Texas El Paso. He is the author of The Indispensability of Intuitions (2025).

‘He has a seriously creepy vibe. I’m not going anywhere with him.’

‘This seems like phishing. I wouldn’t click that link.’

‘Something about this deal feels off. Walk away.’

When people say such things, they are not typically drawing conclusions from a chain of reasoning. The person who avoids getting in the stranger’s car is not thinking: ‘He displayed these three behavioural cues and, therefore, he poses a risk.’ The email isn’t flagged by going through an explicit checklist. The deal doesn’t announce its flaws through a formal audit. In each case, something is simply presented as having a certain character: the man as creepy, the email as fraudulent, the deal as suspect. And yet, acting on these intuitions seems not merely excusable but entirely reasonable. If the man really does strike you as creepy, staying out of his car was probably the smart call – even if you can’t say why.

Despite this, ‘vibes’ and ‘intuitions’ are often dismissed both in daily life and in academic enquiry as irrational or merely heuristic devices. And while we cannot always trust such reactions, they are central, indeed indispensable, to our ability to rationally navigate the world. Philosophers, however, have done surprisingly little to illuminate the rational credentials of these ordinary kinds of intuitions. Instead, they have focused the bulk of their attention on a much more rarefied kind of intuition called rational intuition, which is taken to function primarily in the a priori disciplines of philosophy, logic and mathematics.

My objective is to explain why our everyday intuitive reactions can have such rational force. The key is to see that intuition works in much the same way as perception, in that both can directly present something to us as actual. Once we understand what gives perception this feature, we can see why intuitions might involve exercising the same basic kind of cognitive capacity.

A standard way of characterising rational intuition is in terms of seemings, by analogy with perception. Just as it perceptually seems to you that there is a car in the garage, so it can intellectually seem to you that 2 2 = 4 – the former presenting a physical fact, the latter a conceptual one. But rational intuition and the everyday intuition at work when you decline to get in a stranger’s car are not as far apart as this rarefied example suggests: the philosopher’s intuition is, at bottom, a highly specialised version of the same basic capacity.

To draw these two capacities together, let’s consider a favourite pastime of philosophers: the thought experiment. Philosophers have a penchant for exotica, which is never more clearly on display than in their invocation of thought experiments. Consider two cases that have occupied philosophers for decades – one from ethics, one from the theory of knowledge.

In the trolley problem, the philosophers Philippa Foot and Judith Jarvis Thomson imagined a runaway trolley hurtling toward five people tied to the track. You are standing on a bridge above, next to another bystander. The only way to stop the trolley and save the five is to push the bystander off the bridge. If you do, his body will halt the trolley, but he will die as a result. Many people feel, immediately and forcefully, that pushing him is wrong, even if it saves five lives. But why?

We routinely entertain alternative possibilities in ordinary life

Or consider Carl Ginet’s case involving fake barns. Imagine you are driving through the countryside and see a barn. It looks exactly like a barn; you’re paying attention, the light is good. You form the perfectly reasonable belief that this is a barn. What you don’t know is that you’re in ‘fake-barn country’: the region is dotted with elaborate barn facades, indistinguishable from real barns when viewed from the road. You happen to be looking at the one real barn in this area. Your belief is true, and it seems justified. And yet almost everyone who considers this case has the immediate, firm sense that you don’t really know it’s a barn. But why not?

To sceptics and the uninitiated, these thought experiments can seem fantastical. Because we encounter them in their most dramatic forms, like runaway trolleys and fake barns, thought experiments seem exotic. But properly understood, these imaginative episodes are important tools for sharpening our grasp of key concepts. In fact, their functioning is continuous with something far more familiar: the way we routinely entertain alternative possibilities in ordinary life, wondering what might happen if we take one path rather than another in the proverbial fork in the road.

These imaginings are just thought experiments as they appear in everyday life. Imagine you are deciding whether to tell a friend that his husband has been unfaithful. You picture the conversation, the shock, the hurt that registers on his face. And in that imagined moment, you see that causing such pain is a reason to hold your tongue, even if it’s not a good or decisive one.

How did you determine that this was a reason against divulging the infidelity? It’s not as if you literally see that causing pain is a reason not to do something, nor do you infer it from other things. Rather, in entertaining the possibility, you apprehended his pain as a relevant consideration, as something that counts against disclosure. Its status as a reason emerged not from an argument, but directly from your understanding. It just seems like a reason to hold your tongue.

Intuition’s verdicts simply present themselves, with no organ at work

Notice that this phenomenon also occurs in the thought experiments discussed above. It just seems wrong to push the bystander from the bridge; similarly, it just seems false that you would know it was a real barn in fake-barn country. In both cases, the answer doesn’t arise from an argument. These intuitions arrive unbidden, prior to any deliberation.

These seemings have an unmistakable epistemic pull. Because your friend’s pain seems like a reason, we accept it as such: the seeming is the reason. What is striking is not simply that we have such seemings, but that we trust them. They are involved in shaping our deliberations, guiding our actions, and eliciting belief. They do not merely occur to us; they appear to reveal something about how things must be in the imagined scenario.

For all their ordinariness, however, intuitions remain puzzling. In perceptual experience, we at least have an established framework: the world impinges on our senses, and different perceptual modalities reinforce one another. In the end, we can trace the causal route it takes to produce them. Intuition offers no such apparatus. Its verdicts simply present themselves, with no organ at work and nothing we can point to that they make contact with. Consequently, we rely on them without a clear account of their nature or epistemic authority. But before we can understand intuitions themselves, we need to situate them within a broader........

© Aeon