Truth

This can occur as advocating truthfulness as virtue, forwardness, and generally not trying to cover truth. Also consider it from opposite side of dealing with the effects of lying, either positive or negative. Or even go so far as to show when lies can actually benefit people, such as covering up unfortunate or otherwise unwanted facts about a person for one reason or another.

Commonly the stability of the society or social group is involved and tightly related to the matter.

Half-truths are also common element when dealing with this, essentially wholly true statements that omit certain significant details without appearing to do so. In worse cases one can't even be sure the omitted bit was intentional.