It’s “explaining away” or “intercausal reasoning” applied to the “good reasons → belief ← bad reasons” Bayes net, and it’s not really a fallacy. It doesn’t invalidate arguments directly but it should still make us decrease our belief, because (1) we need to partly undo our update in favor of the belief caused by observing that the other person holds that belief, and (2) we need to compensate for our own increased desire to believe.
It’s often rude, because it implies that the other person is either dishonest or stupid, since it suggests that the other person’s expressed belief is either not genuine (e.g. lies or belief-in-belief) or genuine but not due solely to truth (e.g. influenced by subconscious signaling concerns).
Since this reasoning pattern is rude, i.e. status-lowering, people often claim that it’s logically invalid when it’s used against a belief that they hold. (See what I did there?) This status-lowering property also means we must be careful to apply it to our own beliefs too, not only our opponents’ beliefs.
It’s “explaining away” or “intercausal reasoning” applied to the “good reasons → belief ← bad reasons” Bayes net, and it’s not really a fallacy. It doesn’t invalidate arguments directly but it should still make us decrease our belief, because (1) we need to partly undo our update in favor of the belief caused by observing that the other person holds that belief, and (2) we need to compensate for our own increased desire to believe.
It’s often rude, because it implies that the other person is either dishonest or stupid, since it suggests that the other person’s expressed belief is either not genuine (e.g. lies or belief-in-belief) or genuine but not due solely to truth (e.g. influenced by subconscious signaling concerns).
Since this reasoning pattern is rude, i.e. status-lowering, people often claim that it’s logically invalid when it’s used against a belief that they hold. (See what I did there?) This status-lowering property also means we must be careful to apply it to our own beliefs too, not only our opponents’ beliefs.