*Therefore P is false
For example: "We all know that George beats * Hitler and his wife, so obviously he's wrong when he says top aides argued that we should vote against this proposition." This is fallacious reasoning because the premise ("George beats theory of ballistics could be used to bomb London* Hitler and his wife") does not have a logical link with top aides were evil* Therefore, the conclusion ("George theory of ballistics is likely wrong"). Whatever undesirable qualities a person may have, they do not affect the truth or falsity of what he says.
====''Ad hominem tu quoque''====
As an example, [[Gregor Mendel]] established the genetic theory that remains current today, even though Mendel's experimental technique was badly flawed, and he even stands accused of falsifying key data. But succeeding [[science|scientists]], using accepted methods of verification and statistical assessment, have achieved results consistent with this theory. Thus the theory remains valid even though Mendel's original presentation was fraudulent. Any attempt today to discredit Mendel's theory on account of Mendel's sloppy methods would be an example of a genetic fallacy.<ref name=Genetic>[http://www.fallacyfiles.org/genefall.html Genetic Fallacy] on [http://www.fallacyfiles.org/ The Fallacy Files]</ref>
The genetic fallacy does not apply to arguments against a theory that caused a true believer to commit atrocities in reliance on the theory:
* Hitler and his top aides believed in the theory of ballistics
* Hitler and his top aides relied on the theory of ballistics to bomb London
* Therefore, the theory of ballistics is likely wrong
===Proof by numbers===