Pragmatic fallacy

A pragmatic fallacy is a logical fallacy that occurs when, because something helped someone, it will help for everyone.

Cogito ergo sum
Logic and rhetoric
Key articles
General logic
Bad logic
v - t - e

The fallacy is the bastard child of hasty generalization and anecdotal evidence; it is therefore an informal fallacy.

The fallacy is sometimes confused with an appeal to consequences; this is incorrect. An appeal to consequences uses the effects of holding a belief to argue for the truth value of a proposition, while a pragmatic fallacy uses an example where something "worked" to argue for its general efficacy.

Alternate names

  • It worked for me!

Form

P1: X helped person Y.
P2: (unstated, often unconsidered) Things that work for person Y work for everyone.
C: X will help for everyone.

Explanation

The only way to know whether something is likely to work in all cases is to try it in a representative sample of all cases. (In medicine, usually via double blind studies.) One or two people are not representative of the human race.

A big part of the fallacy is the vagueness of the term "works" — for some people, yoga "works" to make them happy, while for others, it "works" to bring them closer to brahman. This vagueness is exploited by woomeisters worldwide. Customer satisfaction is often used as an argument for a treatment's effectiveness, when it may be nothing more than a placebo effect or their personal regression to the mean.

Examples

gollark: I'm doing some entirely unrelated homework on exponentials.
gollark: It's not even my homework. It's a random page of my textbook.
gollark: As plænned.
gollark: I was saying that this was LyricLy.
gollark: ↓ you

See also

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