A bright line held for no reason except that it is a line can be defensible, because a rule with a visible edge is easier to coordinate around than one requiring judgement each time.
Alexander's argument is that the slippery slope objection is usually treated as a fallacy and sometimes is not, because the thing preventing the slide is the salience of the current line rather than its merit. Moving it once destroys the coordination it provided, since the next case now has no obvious edge to stop at.
In practice
- A policy of no exceptions is worse than the best case-by-case judgement and better than the actual one.
- An organisation that grants one well-justified exception finds the second request harder to refuse than the first.
- Standing
- Builds on Schelling points, which are in the ledger; the addition is the application to slippery slopes.
- Subject
- Law & Politics
- Essay
- Rules that restrain power, and advice on using it