9.3.2 Perfect and Imperfect Duties

Maxims that pass the universalizability test without contradiction in conception Kant would call perfect duties. Such duties are strict, unconditional, and allow no exceptions. They are a) always binding, regardless of circumstances b) correspond to specific actions we must always do or never do c) and generate usually negative rules (prohibitions). Violating these duties always leads to immoral action.

There are of course many more duties we might have that are not so universalizable. Kant refers to these as imperfect duties. These duties are still binding but allow for some latitude in how they are fulfilled. They a) are more general obligations without specific actions b) allow for personal judgment in application c) and are often phrased as positive rules. Examples might include the duty to develop your talents, to help others, to maintain your health, or to promote the general welfare. Such duties can allow for exceptions. For example, “I should study for that next exam” is certainly a duty, though there may be times when you are excused from it (i.e. a personal emergency or a more pressing duty).