Final answer:
Mala in se crimes are inherently wrong and rarely excuse 'good faith' as a defense, whereas mala prohibita offenses are not inherently immoral but prohibited by law, where 'good faith' based on reasonable beliefs can sometimes be a valid defense.
Step-by-step explanation:
The concepts of mala in se and mala prohibita pertain to different types of wrongdoing recognized in legal theory. Mala in se refers to acts that are inherently wrong, such as murder or theft, and which are wrong by their very nature, regardless of whether they are prohibited by law.
Mala prohibita, however, refers to acts that are not inherently immoral but are prohibited because they violate a specific statutory law such as jaywalking or failing to pay taxes. In legal discourse, the use of good faith as a defense is complex and varies between mala in se and mala prohibita offenses.
Generally, for mala in se crimes, claiming that one committed the act in 'good faith'—such as under a mistaken belief that the action was morally or legally permissible—is rarely an acceptable defense. This is because these acts are considered wrong in themselves, and ignorance of the law or a belief that the law is wrong is not typically excused.