[Leader]

"An ad hominem argument, also known as argumentum ad hominem (Latin: "argument to the person", "argument against the man") consists of replying to an argument or factual claim by attacking or appealing to the person making the argument or claim, rather than by addressing the substance of the argument or producing evidence against the claim. It is most commonly used to refer specifically to the ad hominem abusive, or argumentum ad personam, which consists of criticizing or personally attacking an argument's proponent in an attempt to discredit that argument.
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Ad hominem arguments are always invalid in syllogistic logic, since the truth value of premises is taken as given, and the validity of a logical inference is independent of the person making the inference."