Bulverism
Psychogenetic Fallacy
The act of inferring why an argument is being used, associating it to some psychological reason, then assuming it is invalid as a result. The assumption that if the origin of an idea comes from a biased mind, then the idea itself must also be a falsehood.
Origin
C.S. Lewis coined the term "Bulverism" (after imaginary inventor Ezekiel Bulver) in a 1941 essay, later expanded and published in 1944 in The Socratic Digest. The logical fallacy assumes without evidence that an opponent's position is false, then attributes the belief to psychological, social, or ideological causes rather than engaging with the actual argument. Lewis illustrated it through Ezekiel Bulver, who learned that "refutation is no necessary part of argument. Assume that your opponent is wrong, and explain his error." Lewis's central point: "You must show that a man is wrong before you start explaining why he is wrong." The fallacy combines circular reasoning, the genetic fallacy, and ad hominem with presumption.