Steelman
Slippery slope
Also called domino fallacy, thin end of the wedge, camel’s nose.
Claiming one step will inevitably set off a chain of ever-worse consequences, without good evidence for each link.
What it is
Arguing against a first step by asserting that it will trigger a chain of events ending in disaster, when the likelihood of that chain is exaggerated or unsupported.
The pattern
If A, then eventually B, then C… then Z (terrible). We must not allow Z. So we must not allow A.
An example
“If we let students retake one test, soon they’ll expect to redo every assignment, grades will become meaningless, and our diplomas will be worthless.”
Each step is asserted, not shown. A school can allow one retake and still keep standards, because policies can include limits.
Why it fails
Every link is a prediction that needs support, and uncertainty compounds. If each of three steps is 80% likely, the whole chain is only about 51% likely (0.8 × 0.8 × 0.8 = 0.512). Slippery-slope arguments usually present the chain as inevitable while giving little or no evidence for the links.
When it’s not a fallacy
Most lists skip this part. Calling a fair point a fallacy is a mistake too.
It can be fair when
- Each step is backed by evidence, such as documented precedent effects or a known pattern of escalation.
- The argument is about a genuine precedent: “If we make an exception for you, fairness requires the same exception for everyone in your situation” can be sound.
- The claim is honestly probabilistic (“this makes B more likely”) rather than a guaranteed slide to disaster.
Try one
A question from the app. The wrong answers are its usual look-alikes.
School board. The proposal is a prayer club run by students after the last bell, like the chess club. The district’s lawyer: “Staff can’t lead it or join in, and district policy bars prayer at any school event. The courts have upheld that policy twice.” Parent: “Clubs like this don’t stay in one room. First a table at lunch, then a prayer before the pep rally, then a coach leading it before games. By the time my daughter’s a senior, praying will be part of making the team. I’m voting no.”
What’s the flaw?
The lawyer said staff can’t lead the club and prayer is barred at school events, a rule the courts have upheld. The parent’s chain needs exactly those things to happen and gives no reason they would.
A fair reply
“Staff can’t lead it, and a pep rally is a school event. Which step gets past that policy?”
Often confused with
- Appeal to emotion
Slippery slopes often lean on fear, but their specific error is the unsupported chain of consequences.
- False dilemma
A false dilemma limits the options. A slippery slope exaggerates where one option leads.
Where the name comes from
On a slippery slope, one step down and you can’t stop sliding to the bottom. The domino fallacy pictures a row of dominoes: tip one and they all fall. A wedge goes into a log thin end first, and each blow drives it deeper until the log splits. Camel’s nose comes from a fable: a camel asks to put its nose in the tent, and soon the whole camel is inside.
Sources
- Fallacies, Bradley Dowden, Internet Encyclopedia of Philosophy
In the app
Practice spotting it on arguments that sound real.
Steelman has more examples of slippery slope, how to answer it in a real conversation, and practice rounds that mix it with its look-alikes, so you learn the difference, not just the name. Coming soon to iPhone and Android.
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