Compunction is guilt, unease, or doubt over an action or a proposed action. It suggests that an activity may be ethically or morally questionable. It is commonly used in the negative as in "having no compunction (to, or against)" or "without compunction" -- suggesting that there ought to be some moral qualms or hesitation involved.

Example:

"He had no compunction against ruining the lives of others."

"Their leaders had no compunction about sending troops to die in a futile attack."

"The swindlers stole from their investors without compunction."