The logical fallacy of experience

6 min readMar 8, 2022


An often-repeated quote or quotes, are:

“Experience is the best teacher”

“Failure is the best teacher”

In a word: no. This logic is not only often wrong, but frequently leads to dangerous conclusions.

Experience does not always teach

Experience only teaches what you actually choose — or are able — to learn from it. There are no end of people who have done something for decades and still don’t know how to do it properly; people who have experienced something but still have no idea about it or how it works.

You wouldn’t — for example — be able to learn rocket science simply by watching enough rocket engineers and scientists figure out how to make rockets. You could learn little bits of it, but much of the knowledge required to understand how it works would elude you.

You don’t need to experience something to know about it

Let’s think of an obvious example of something we know without experience. You may be sitting in a chair right now reading this article. How do you know your chair doesn’t taste like chicken? Have you tried eating it?

The person who thinks you have to experience something to know it will immediately chime in, saying “well you clearly don’t know it tastes like chicken unless you taste it”. Of course, in our minds we know our chairs don’t taste like chicken, because:

  • They’re made of e.g. wood or metal
  • We know that wood and metal are very difficult or impossible to chew, we learned in biology that we can’t digest them
  • We know from wooden and metal utensils what they taste like, etc, so we know they don’t taste like chicken

In other words, we didn’t have to actually experience eating a chair to know it doesn’t taste like chicken. We can use our knowledge — and perhaps also knowledge gleaned from different, but applicable experiences such as tasting something made of a similar material — to know without having to actually do it.

You can often make correct (limited) conclusions from incomplete data

The fallacy of “you must have experienced something to know about it” can be disproven relatively easily in many scenarios where the statement or fact in question is of a broad scope.

As an example, let’s make an assumption that no pizza recipes contain pineapple. If this assumption is true, we can determine whether a recipe is a recipe for pizza by checking each ingredient in turn. If an ingredient is pineapple, we can stop: we have our answer. Since no pizza recipes contain pineapple, and this one does, we can conclude that it is not a pizza recipe without looking at the rest of the ingredients.

If the first ingredient on the list is pineapple, we don’t need to know what the other ingredients are to know that this is not a pizza recipe — provided, of course, that our initial assumption was correct.

In much the same way, this applies to practical situations in real life. Statements of “this is the best game of all time” or “nothing could ever be stronger or faster than X” are often easy to disprove, because you only need to find one counter-example to disprove them, often not requiring a detailed analysis of every aspect of it.

Obviously, some care has to be taken not to operate on faulty assumptions (such as an assumption that goes too far, assuming that its point holds in places where it may not), as if an assumption is faulty then the rest of the logic breaks down.

Experience frequently gives incorrect knowledge

All throughout history, before the advent of the scientific method, experience was frequently our worst enemy in discovering knowledge.

An easy example of this would be the concept of objects being equally affected by gravity regardless of their mass, as in Galileo’s famous experiment. It was Aristotle’s belief that objects fell at speed depending on their mass, which Galileo’s experiment (and others before him) proved to be false.

If we were to use experience, it would seem to tell us Aristotle was right; if I drop a piece of paper it falls quite slowly. If I drop my phone it falls quickly. Since my phone is heavier than the paper, it would appear that my phone falls faster because it weighs more — an incorrect conclusion.

It is also experience that teaches us prejudice in many forms. A person might meet several people in white vans who drive badly; that person, from their experience, concludes that people in white vans are bad drivers. Of course, their experience is a tiny sample size, and has led them to incorrect knowledge. Some elements of racism and other prejudices— such as assuming all gay men are flamboyant and have lisps — come partially from the fallacy of ‘experience’.

The history of medicine, in particular, suffered from the problems of thinking experience equals knowledge. Physicians — even those of good intent — would prescribe a random bunch of herbs or other things as a cure for an ailment, and if it worked, it would appear the medicine healed the person. On the other hand, if the person didn’t recover, it could simply be that the medicine wasn’t strong enough, or the disease was too far along: correlation was seen to prove causation, but only if it produced the desired result.

Confirmation bias and correlation-causation fallacies are both serious problems when it comes to assuming experience equals knowledge.

The more dangerous side of experience

Most of the examples I have given, thus far, are relatively harmless. Today, however, there is an extremely malicious and harmful version of this problem around: what is sometimes called the “post-truth” era.

Plenty of us have seen far-right commentators tell people to, for example:

“Do your own research on vaccines”

“Don’t trust this big organisation, use your instincts and common sense”

These commentators are not stupid. They are smart and malicious; they know very well that for most of their audience, telling them to “do their own research” after presenting many insidious views about a subject will result in them looking for articles that confirm the biases the commentator has just given them. If, for example, Ben Shapiro tells his audience to question vaccines and how they are made, his audience will go looking for articles “proving” they are made in some particular way that causes Satan to infest their souls or whatever other nonsense he has said.

By telling people to trust their “experiences” and not their knowledge, you can easily manipulate them to draw false conclusions about topics that are not extremely simple, because experience frequently fails to consider all factors that could affect the situation in question. This is exactly why the scientific method was created: to get away from using experience as a sole factor in determining anything.


The point of this article is not to suggest that everyone is an expert on everything. It is to suggest two things:

  • Experience doesn’t necessarily equal knowledge or competence
  • A lack of experience doesn’t necessarily equal a lack of knowledge or competence

In many fields, the latter is particularly true. Programmers, for example, do not necessarily need to have used a particular programming language to know conceptually how it works, because most programming languages work in a group of similar ways (imperative, object-oriented, interpreted, compiled…), and share many similarities.

I don’t need to have personally developed or created vaccines to know that they work. I know enough biology to understand the mechanism by which they work; one of the main reasons that uneducated people are so prone to doubt vaccine effectiveness due to propaganda is that it is effectively impossible to explain them in ways that can be “proven in front of you”.

For instance, a vaccine works by training your immune system to fight invaders. If you try to explain that, you have to go into how your body produces white blood cells in bone marrow, and short of taking someone’s body apart, you can’t prove that in front of someone. They’ll tell you a model of bone marrow is a fake made by Big Pharma to sell drugs or some other madness; you can’t prove it to them because they have fallen for the idea that only things they can touch and see and experience can be true.