Appeal to calmness

Overview
An appeal to calmness may be used as a rhetorical deception wherein a legitimate argument is answered by a diversionary claim that the arguer is clearly upset, diverting the topic away from the substance of the argument and on to the subject of the arguer's mood (often stated as some form of anger).

Effectiveness
The appeal to calmness can be especially effective if the arguer is genuinely upset in some way, as the discounting of the argument may successfully push the arguer "over the edge" into a truly irrational and contemptible display of anger, thus further undermining of the arguer's credibility and making the "calm" responder appear reasonable and sane by comparison.

Legitimate Usage
In a situation where one or more people are arguing incoherently, speaking over each other, or otherwise not making understandable arguments, it is legitimate to point this out – but it must be followed up by an attempt to map out what each arguer is actually saying, rather than treating the claim of emotionality itself as a refutation.

Related
The appeal to calmness bears some relation to some other types of rhetorical deceptions:
 * It is a form of ad hominem attack in that it responds to the argument by undermining the arguer's credibility.
 * It is an appeal to emotion in that it operates on emotions rather than on the substance of the argument.
 * It is a combined argument by ridicule and appeal to guilt, as it may make the argument seem ridiculous by making the arguer (and hence the arguer's motivations) seem ridiculous; it also subtly implies that the arguer is irrationally overreacting and that their arguments are irrational as well.