argumentum ad hominem

In ulterior motives, SB has written a post about being accused of harbouring ulterior motives in responding to a comment on blogs.

A discussion has followed up on ad hominem type of fallacy. This discussion is between an idiot I don’t allow to comment on my blog. Being stupid is bad enough, worse is when one is stupid and not know it.

I wrote in that post

A mere verbal abuse in the absence of an argument, however, is not ad hominem nor any kind of logical fallacy

then the idiot comes and writes

Nothing you maintain is stupid can only be true because you are an atheist who hallucinates that stupid can only apply anyone but you.

which is an ad hominem, since instead of responding to my argument, he makes his argument about my atheism and argues that as an atheist, my argument isn’t valid.

If in my response to him, I told him I don’t hallucinate but he is an idiot, I have not committed a fallacy for there is no inconsistency between his stupidity and my not hallucinating.

In examining the burden of proof in arguments, it has been found, per[?] Douglas Walton that

traditional informal fallacies like the petitio principii, argumentum ad hominem, and argumentum ad ignorantiam are revealed as

(a) not fallacies in many instances, but forms of plausible reasoning that can be reasonable arguments to shift a burden of proof, and

(b) extremely important types of criticism in argumentation that can have the legitimate function of shifting a burden or weight of evidence against, or in favor of presumptions in an argument.

I thought I should clear this up.