> "Slippery slope" is also most commonly a fallacy, which a lot of people seem to ignore.

I don't ignore it. I reject it outright. Politics especially (and human behavior, more generally) operates on slopes. Allowing x quite literally can and does often lead to x + 1. If x + 1 is unacceptable, then it's perfectly legitimate to oppose x on the grounds that it will produce x + 1 (even if we all could agree that x is itself acceptable).

The fallacy, such that it exists, is that the truth value of x exists independent of whether it will lead to x + 1. You can't disprove something about x by arguing that it will produce x + 1. That's all well and good, but it's not what anybody's talking about when they invoke a slippery slope argument in the context of human systems.

Slippery slope arguments only retain validity of each link in the chain is demonstrably probably.

Even then, for something like resisting dangerous speech, what does the slope matter? If the original thing is good to do, don't worry about the slippery slope, just make the right decision. Then of it goes to far and you're on the edge of a slope, that's where you fight.

If guidelines about violent speech are abused, then fight to fix it. Don't avoid the correct decision just because doing it right will be hard work.

Because it is so easy to stop the government from doing absurd things once it gets the power to do them? Like kicking in a door guns ablazing because someone might have smelled weed? Yeah, we stopped that the first time it happened, didn't we...

Literally any thing the government might have authority over or acknowledge as a freedom could have things get absurd. So the argument that it might get absurd doesn't mean the thing is wrong. It just means that, likely any action, there's potential for consequences, and you deal with them.

You don't back down from a good thing just because it might be hard to implement. So then it just comes down to whether you think removing speech that incites violence is a good think or not. If you think it's good in itself but could be abused so maybe not do it? No, you do it and deal with the hard questions that come along every time you make those decisions.

"We need to stop any speech that we think is wrong!"

Well, what if the definition of "we" changes? What if you become the minority and the majority wants your speech limited?

The only reason why we have things like gay rights, women's rights, civil rights, etc, is exactly because of free speech. The speech at that time were the minority but were protected by the Constitution.

If we don't respect the rights of those that we disagree with, when (not if) they come into power, they will use those same rights to quash our free speech. And remember that almost half of the US voted for Trump who is demonstrably the worst president in US history. If there is a smarter, more palatable right-wing candidate (ex. Tom Cotton, etc), we really could see a Republican president in office by 2024. And they would use that hammer that the left have been trying to use to quash that free speech.

We have the Constitution and Free Speech for a reason. And it has worked for centuries now.

Again, you're talking about what might happen. If something goes wrong you address the problem. Your argument could be applied to any law: "We can't let towns and counties and states to set speeding limits! If they do, the next thing you know they'll limit things to 40 mph, and after a while 30 mph. And poof! One day you'll wake up and over 5 mph would get you a speeding ticket!"

This internet cliché whereby someone in a debate circle declares something a formal fallacy, and then a million internet commenters turn it into a meme, should stop.

Slippery slopes can be shown throughout history. Trump himself has put us on a slippery slope it seems. No, it doesn't matter that some college debate class student included it on a list of debate fallacies on Reddit. It's an idiom to succinctly describe a chain of causality.

> It's an idiom to succinctly describe a chain of causality.

Right, and the fallacy is that it's being pre-attributed to a sequence of events that hasn't happened yet.

Again, it's a boring argument and adds nothing to the discussion.

The point is not that one thing never leads to another in this way, but that the possibility of a future slippery slope doesn't support an argument by itself.

It is absolutely not a fallacy, as Naval Ravikant points out, given the large numbers of slippery slopes that have played out in the historical record. I have no idea why the belief that it is a logical fallacy is so widespread.