Appeal to guilt

Overview
An appeal to guilt is a form of emotional argument in which the target is encouraged to feel guilty or shameful for holding the views for which they are arguing, often by ascribing unprovably-false motives to the target, or motives which may seem "obviously true" even though they are not.

Also known as: appeal to shame

Validity
The "appeal to guilt" is acceptable as a way of shaming an opponent into accepting an otherwise-valid argument when logic and reason have failed. Use of the "appeal to guilt" does not automatically invalidate the substance of the argument in which it is used; it is more of a signal that there may be unspoken assumptions which need to be examined more closely.