What are FALLACIES, and what to do the next time you’re in a Tumblr brawl and some asshole is like “omg fallacy so you’re 110% wrong.”
This is the other part of the thing on logic that we’re doing, and it’s the thing that most people who’re not philosophers run into: fallacies. Anyone who takes a 100 level philosophy course learns about them and then starts throwing them around like an “I win” button in an argument. Basically, most people think that pointing out a fallacy means they’ve won, even if they haven’t really done anything with the argument. This is bullshit, especially when you consider that logic (as a system) works in and with cultural contexts. So a man who dismisses a woman’s argument about sexism using an anecdotal fallacy (or a white person dismissing racism in the same way) is a jackass for not recognizing that his position in the social world blinds him to things outside his lived experience. We’ll get to more abuses of fallacies later on.
Anyway, there are a whole bunch of different kinds of fallacies that we can talk about, but they generally fall under two different types. I say “generally” because logicians and other philosophers will fight to the death over what counts as a fallacy, but most will agree that there are two categories. So, the first category is what we call “formal fallacies,” which are pretty much errors in the form of the argument, or how the argument is put together; and there are “informal fallacies,” which have to do with the content of the argument and not how they’re put together. If we’re going to make it simple, a formal fallacy is like a spelling error: it has nothing to do with the meaning of the word, just how it’s put together. An informal fallacy is like using the wrong definition of the word: the word could be spelled correctly, but it doesn’t mean what we think it means.
This difference is SUPER important because a formal fallacy doesn’t say shit about the premises or the conclusion, just how you got there. So, in a deductive argument, which is a fancy way of saying an argument where the conclusion follows from the premises, a formal fallacy is basically saying that the conclusion doesn’t follow logically from the premises. So the argument is invalid because the structure is wrong, not because the premises or conclusion is incorrect. In an inductive argument, which is an argument where we’re pretty sure that the conclusion follows from the premises, formal fallacies are basically where we screw up our probabilities. Again, it doesn’t really have anything to do with the content, but it has everything to do with the way you put together your argument.
Informal fallacies are the ones that most assholes like to toss out in the middle of an argument without actually knowing what they mean. Basically, an informal fallacy is a problem with the content of the argument that pretty much makes the argument bullshit. So, for example, the fallacy of composition, which basically says that if an argument says something true of the part, it must be true of the whole, is pretty much bullshit because a single member of the group doesn’t reflect the whole group absolutely. Now, this is a little more complicated because some of these (like logic itself) are grounded in the perspective of the people in the argument and are subject to biases, but generally they work to evaluate arguments on the basis of what they’re saying, and not how they’re structured.
Where people fuck up is with shit like how fallacies deal with truth and validity. So if you have a formal fallacy, that usually means that the person got to the conclusion in a messed up way, or that there’s no logical connection between the two, but not that the premises or conclusion is necessarily false. Like, “If it is night, the moon will be out. The moon is out. Therefore, it must be night.” So, this is a fallacy because it doesn’t talk about other reasons the moon could be out and it not be night, like a solar eclipse, maybe. The conclusion could be true, but that doesn’t necessarily mean that it must be true. But yeah, like I said before, formal fallacies don’t give a shit about the truth of the premises or conclusion, just that they follow from one another, and in the case of the example I gave the premises don’t follow from the conclusion. But that doesn’t mean that either the premises or the conclusion aren’t true.
Informal fallacies are failures to prove the point and are usually related to the evidence that someone puts into their argument. Like the fallacy of composition above; in order to prove an argument that used the fallacy of composition correct, you’d have to look at every part of the group in question and demonstrate that it is similar to the part you’re using as an example. Pretty much, an informal fallacy has everything to do with what’s in your argument and how you’re supporting it, and not with how you’re structuring it.
Where this gets tricky is with conversations about groups of people (i.e. in social justice circles) where the fallacy of composition and division are often tossed out to discredit reactions to systemic problems, without realizing that most arguments about power majorities (white people, men, straight people) are grounded in a critique of the system that goes about producing these individuals. So, if you can demonstrate that the system has a particular element in it, it follows that the thing that the system produces will have that element in it. So, when you say “not all men,” as a response to sexual violence, you’re kind of missing the point that people are concerned about the culture that tells men that sexual violence is okay. Also, you’re committing the “onus probandii” fallacy. Okay, so since I’ve started using latin, this means I should get to explaining what certain fallacies are.
So, this wikipedia page pretty much defines some of the fallacies for you. There are other lists, some of the overlap, and none of them are comprehensive because philosophers can’t agree on what counts, and other people in other areas keep trying to throw shit in there.
Since the lists of fallacies don’t seem to agree with one another (and neither do the textbooks), I’m gonna go with the SEP’s first fifteen fallacies in individual posts: if anyone wants me to do some from other places, you can drop me an ask.