DH0 Name-calling: "The author is a self-important dilettante" is really nothing more than a pretentious version of "u r a fag." Articulate name-calling carries just as little weight as the crude kind.

DH1 Ad Hominem: Saying an author lacks authority to write about a topic is a particularly useless variant—good ideas often come from outsiders. The question is whether the author is correct, not credentialed.

DH2 Responding to Tone: If the worst thing you can say about something is to criticize its tone, you're not saying much. Is the author flippant but correct? Better that than grave and wrong.

DH4 Counterargument often misses: more often than not, two people arguing passionately are actually arguing about two different things. Sometimes they even agree but are too caught up in the squabble to realize it.

DH5 Refutation requires a smoking gun—a specific quote you can show is mistaken. If you can't find an actual quote to disagree with, you may be arguing with a straw man.

Even at DH5, dishonesty appears as picking off minor points—correcting grammar, names, or numbers. Unless the opposing argument depends on those things, the only purpose is to discredit the opponent: a sophisticated form of ad hominem.

DH levels don't set a lower bound on convincingness, but they do set an upper bound. A DH6 response might be unconvincing, but a DH2 or lower response is always unconvincing.

An eloquent speaker can give the impression of vanquishing an opponent merely by using forceful words—that is probably the defining quality of a demagogue. Naming the forms of disagreement gives critical readers a pin for popping such balloons.