The amount fallacy
Just because some amount of something is bad doesn’t mean any amount of it is bad
Finding a new star nobody has found before is rare, but it happens—the same goes for fallacies. Errors in reasoning happen all the time, and most of those times people don't bother looking up the specific name of that error; identifying it as an error suffices. When an error is too common, somebody eventually bothers to name it and thus a fallacy is born. It's convenient to name fallacies because it saves time trying to disentangle the logic; you can just google the fallacy, and soon enough you will find examples and explanations.
I believe I have found a new fallacy, but unlike most new fallacies, this one has been under our nose for god knows how long.
I've decided to coin it the "amount fallacy", although a close second was "toxic fallacy", and also "sweet spot fallacy". This concept is far from new, but it doesn't seem to have a name. It has already been spread around in toxicology for at least four centuries with the aphorism "the dose makes the poison". The idea is simple: everything is toxic. Yes, even water can be toxic, it all depends on the amount.
This concept applies absolutely everywhere, which is perhaps why nobody has bothered to name it. Is hot water good or bad? It depends on what precisely you mean by "hot"; it can be 40°C, 60°C, 1000°C, or just about any amount. Since language is often imprecise, the fallacy can sneak by very inconspicuously.
It can be spotted much more easily by realizing sweet spots; too little or too much of something is bad. Water above a certain temperature is bad, but so is water below certain temperature. A similar notion is the Goldilocks principle.
As obvious as this fallacy is, it's committed all the time, even by very intelligent people.
Take for example income inequality. The debate about inequality is still raging in 2020, perhaps more than ever, and the positions are very clear: one side argues it's possible for income inequality to be "too high" (and in fact it already is), the other side argues income inequality is inevitable (and in fact desirable). These two positions don't contradict each other; all you have to do is accept that there is a sweet spot. It's that simple.
Surely it cannot be that easy. Surely people must have realized this obvious fallacy while discussing income inequality. Of course they have! But they also haven't named it. This makes it so people fall into the same fallacy over and over, and it has to be explained why it's a fallacy over and over.
What a piece of work is a man! How noble in reason, how infinite in faculty! In form and moving how express and admirable! In action how like an angel, in apprehension how like a god! — William Shakespeare
People often aggrandize the intellectual capabilities of the human mind, so they assume intelligent people surely can't be making fallacies this ludicrous, and if they do; surely they would realize when somebody points that out, and if they don't; surely somebody would record this kind of fallacy so others don't fall for it. But remember that it took thousands of years after the invention of the wheel before humans came up with the brilliant idea of putting them on luggage (around 50 years ago). So don't be too quick to assume the grandioseness of the human mind.
Here's another example: immigration. One side argues immigration enriches the culture of a country, the other side argues immigration dilutes the national identity. Perhaps there's an amount of immigration which isn't too much or too little? Yes, there's some people that argue precisely this, except without naming the fallacy.
Another example: exposure to germs. Too many germs can certainly overwhelm any immune system, but too little weakens it. The immune system requires constant training, and in fact there's a theory that the current allergy epidemic is due to children's underexposure to germs (hygiene hypothesis).
A more recent example: epidemic mitigation measures. Many people argue that masks must be compulsory, because not wearing them "kills people", this is of course very likely true. But what part is missing in the argument? The amount. Everything kills people. Just driving a car increases the probability that you will kill somebody. Driving cars kill people; that's a fact. But how many? Richard Dawkins—a famous evolutionary biologist, and author—recently made precisely this fallacy in a popular tweet.
The same applies to anything antifragile, but the examples are countless: recreation, safety, criticism, politeness, solitude, trust, spending, studying, exercise, thinking, planning, working, management, circumlocution, sun exposure, child play, child discipline, vitamin consumption, etc.
Technically this falls into the category of hasty generalization fallacies; the fact that some rich people are greedy doesn't mean all rich people are greedy. In particular it's an imprecision fallacy, similar to the apex/nadir fallacies, except in terms of amounts.
The form is:
1. Some amounts of X are bad
2. Some amounts of X don’t represent all amounts of X (ignored)
∴ All amounts of X are bad
The amount fallacy happens because premise 2 is ignored. An exception could be cheating: a small amount of cheating is bad, even more so a large amount; the amount of cheating doesn't change its desirability.
Perhaps this fallacy already has a name, but I don't think so; I've looked extensively. Even if it's too obvious, it needs to have a name, because people commit it all the time.
So there you have it. Any time somebody says something is bad (or good) because some amount of it is bad, be on your guard; that doesn't mean any amount of it is bad.