If you're following this blog but not Diane Levin's Blog The Mediation Channel, I have good news for you. Diane is an extremely focused, disciplined and lively writer. She's also one of the brightest and most canny negotiators, mediators and negotiation trainers I know.
Diane describes her series, Fallacious Argument of the Month, as follows:
With the goal of promoting clearheaded and reasoned debate and improving discourse, each month I skewer a different fallacy.
Before giving you entree to this excellent series, let me first note that these arguments do not justify any movement in your negotiation position. Remember - you need a new number and a new reason to counter that new number. If your mediator or negotiating partner expects you to give up something, he'd better have a darn good reason for you to do so. If you're a lawyer representing a party, you can feel your client figuratively or literally tugging on your sleeve when you offer more or agree to accept less in the absence of a justification that makes business sense.
Argumentum ad Hominem (this one is so irritating it can create impasse where none previously existed)
The Misleading Ellipsis (to which I add this caution ~~> the quickest path from respected advocate to deceitful scoundrel is the misleading ellipsis - Judge, Arbitrator, Mediator and Opponent will all distrust your bona fides from that date forward; if you can't think of a better argument, fall on your sword on this issue and create a better one just over the next hill).
Diane adds one new fallacious argument every month. I'll endeavor to keep up with her. But more reliably, get her RSS feed, add it to your google reader and never again be without the wisdom of this brilliant mediator and negotiation trainer and consultant. That's her smiling face at top. Visit her often! at The Mediation Channel.