Imperfect Duty?

A duty must be perfect. You have to do it, or you don’t; there is nothing in between. To say that something is not a duty but it would be a very good thing if you did it, is not to say that it is half a duty, a third of a duty, or ninety percent of a duty. A duty is always a hundred percent, or it is nothing.

That is not to pretend that every obligation is an equally strict requirement – of course it isn’t. There is a definite law against killing random passers-by in the street and your teacher is adamant that you do your homework, but no one thinks those two duties are in any way comparable, yet they are both absolute. As long as no room for options are given by the recognized authority, the demand is total, which is to say it is a duty, although nothing is said about the importance of that particular duty.

This is a mere conceptual analysis of the term “duty” and I don’t mean to express anything about its practical importance. Some ethicists think duty is everything while some leave it on the fringe of morality, but it is to be expected that the simple definition is the same for everyone. When the task at hand is accompanied by an absolute expectation that it is fulfilled, we call it a duty, if not it is a recommendation. The latter term may vary in strength depending on the authority of the advisor, ranging from a friendly suggestion to something close to a demand, but it is never absolute. That is reserved for the word “duty” which always designates something absolute, something perfect, that is.

Recognizing this it may seem odd that Kant the philosopher introduces the combination “imperfect duty” and thereby employs a contradiction in terms. But he is forced to do it since ethics for him is duty and duty only, while at the same time there clearly exist ethical considerations that cannot be fully covered by laws and commandments. There is an unlimited amount of good deeds that we could conceivably do although it would be unreasonable to demand it. The saintly character has attained a height of moral life that is beyond the reach for most of us, and we need a way to convey the idea that their conduct is highly admirable. Since they act morally they necessarily act dutifully in Kant’s terminology, but because we don’t absolutely have to act like them, the qualifier imperfect is added. The result is an artificial construction that doesn’t make much linguistic sense: It says we have duties that are not duties. 

What this actually means, translated into a language we are more familiar with, is that the notion of duty fails to cover the entire domain of ethics even for a deontologist. Another term is needed, and the only way the term “imperfect duty” can be thought to fill the gap, is if it represents something that is not a duty at all.