The acceptability of the argumentum ad misericordiam in equity and criminal sentencing is explained by the nature of the decisions to be reached in those contexts. Both equity cases and discretionary sentencing decisions involve attempts to do justice and are thus different in nature from questions of fact or law. Doing justice requires looking at hardships that already exist and deciding whether imposing a penalty or a remedy would cause a greater hardship in a particular case than normally accompanies that sentence or remedy. In such cases, an argumentum ad misericordiam is not a fallacy because it is actually relevant to the decision.

Ruggero J. Aldisert, Agatha D. Aldisert, Logic for Lawyers- A Guide …, loc. 1038