We are warned that an argument made with a predecided conclusion does not evidentially entangle with the truth it claims to address, and thus is no evidence of that claim.
Recall that observation E is evidence for hypothesis H iff P(E|H)>P(E|¬H). What do the variables mean here?
E: there’s a convincing argument for the predecided conclusion
H: the predecided conclusion is really true
P(E|H): probability that the clever arguer can make a clever argument, given that the conclusion is true
P(E|¬H): likewise, given that the conclusion is false
What the commentary from “The Bottom Line” leaves out is that making a convincing argument is a nontrivial task. For many false claims, a clever arguer with ordinary resources cannot make a convincing argument. If it’s typically easy to make a convincing argument for something false, you’re convinced by the wrong things.
Thus P(E|H), in this case, would usually be greater than P(E|¬H). An argument for a claim from a clever arguer only clearly proves that the arguer wanted us to believe it. A convincing argument for a claim — and if the argument isn’t convincing, you’d ignore it — proves that the claim has convincing arguments for it accessible to that level of arguer, which is correlated with the claim being true.
But maybe I decided at the start that clever arguments for predecided conclusions are actual evidence, thereby breaking the entanglement of the rest of this essay. Well, are you convinced anyway?
Clever arguers give weak evidence, not zero
Link post
Followup to: The Bottom Line
We are warned that an argument made with a predecided conclusion does not evidentially entangle with the truth it claims to address, and thus is no evidence of that claim.
Recall that observation E is evidence for hypothesis H iff P(E|H)>P(E|¬H). What do the variables mean here?
E: there’s a convincing argument for the predecided conclusion
H: the predecided conclusion is really true
P(E|H): probability that the clever arguer can make a clever argument, given that the conclusion is true
P(E|¬H): likewise, given that the conclusion is false
What the commentary from “The Bottom Line” leaves out is that making a convincing argument is a nontrivial task. For many false claims, a clever arguer with ordinary resources cannot make a convincing argument. If it’s typically easy to make a convincing argument for something false, you’re convinced by the wrong things.
Thus P(E|H), in this case, would usually be greater than P(E|¬H). An argument for a claim from a clever arguer only clearly proves that the arguer wanted us to believe it. A convincing argument for a claim — and if the argument isn’t convincing, you’d ignore it — proves that the claim has convincing arguments for it accessible to that level of arguer, which is correlated with the claim being true.
But maybe I decided at the start that clever arguments for predecided conclusions are actual evidence, thereby breaking the entanglement of the rest of this essay. Well, are you convinced anyway?