The point where you don't go down the slope is when you recognize it and you don't know what is at the end of it's long tail. The guidance is built in.
"We can't have police, this will lead to a slippery slope that will lead to a 1984 police state."
"We can't not have police, this will lead to a slippery slope that will lead to Mad Max anarchy and roaming bands of killers and warlords riding in really awesome-looking semis."
That's the entire problem with the slippery slope! Two entirely conflicting, equally compelling arguments can be construed with it, starting from the same simple question - "Should there be police? Yes/No?"
Just because the bottom of a slippery slope looks awful, or can't be seen isn't a reason to do, or not do something - because I can construct a million awful slippery slopes for any action you do, or not do.
A slippery slope argument eliminates all nuance from a question, and provides no guidance for answering it well. That's exactly what makes it a logical fallacy.
> Just because the bottom of a slippery slope looks awful, or can't be seen isn't a reason to do, or not do something - because I can construct a million awful slippery slopes for any action you do, or not do.
Who said anything about using a slippery slope for the _only_ justification to do or not do anything?
You said "Slippery slope arguments provide exactly zero guidance for as to when it is reasonable to stop going down the slope, which is what makes them utterly useless" and I disagree that they're utterly useless. Sure, it doesn't provide guidance. Why does it need to? As you go down the slippery slope you learn about the possibilities you should consider. You also learn about the possibilities you can ignore. It's a risk assessment tool and it's incredibly useful.
I'm not sure how you can deny that putting all the chips on the table, thinking about, and debating all the possibilities has no benefit when you're assessing an idea or an action to take. There's nothing wrong with _considering_ possibilities and going down the slippery slope. It's often a very useful exercise.
