Recipe

Repair a fallacious argument

Use when: an argument's conclusion might be worth defending, but its support has a recognizable defect

Goal: a rewritten argument that keeps the arguer's point as far as the evidence allows and has no fallacy

Taught in Repairing fallacious arguments

1. 1

   Write the conclusion, then each premise, in your own words. Leave out tone and extra words.

   Example

   "Only a fool would vote against the new bike racks; the school board member who did can't even ride a bike." Conclusion: the bike racks should be approved. Premise: the board member who voted no can't ride a bike.

   Why: you can't find a defect in an argument until you can see its parts.

2. 2

   Are the premises relevant? Are they enough? Is something assumed? Is the language doing the work? Stop at the first problem.

   Example

   Relevant? No. Whether one board member can ride a bike doesn't bear on whether the racks are a good idea.

   Why: the first question that fails narrows the defect to a family, using the table in Chapter 5, Section 1, so you know where to look.

3. 3

   Match the problem to the fallacy it fits. Say in one sentence what the premises fail to do.

   Example

   Ad hominem: the argument attacks a person who disagrees instead of giving a reason for the racks.

   • an off-topic premise — a relevance fallacy (Chapter 5).
   • too few or lopsided cases — hasty generalization (Chapter 6).
   • an unproven assumption — a presumption fallacy (Chapter 6).
   • a cause beyond the evidence — a causal fallacy (this chapter).
   • a shifting word, sentence, or part-whole move — a language fallacy (this chapter).

   Why: each named fallacy points to a standard repair, and the one-sentence explanation keeps the name from being a mere label.

4. 4

   Decide whether to strengthen the support, weaken the conclusion, or both.

   • relevant evidence exists or can be found — strengthen the support.
   • the evidence is thin and can't be improved now — weaken the conclusion.

   Why: these are the only two honest ways to make premises and conclusion fit.

5. 5

   Write the new argument. Then run the four questions on it again.

   Example

   "The school should approve the bike racks. Forty students bike to school, and right now they lock their bikes to the fence, which blocks the walkway."

   Why: a rewrite can smuggle in a new fallacy, and rechecking is the only way to catch it.