I have argued that the concept of moral duty is, in a sense, bogus. Moral duties, rules and obligations do not exist independently of us in the same way that physical and mathematical realities do. We certainly have moral intuitions, that is, feelings and judgments that some types of actions are morally forbidden, others are allowed and others are mandatory. But these intuitions are socially constructed. Moral rules are independent of individual human beings in that they come from the culture that an individual lives in or was raised in. But they are not independent of all human beings in the ways that physical things and (arguably) mathematical entities are.
Once you recognize the peculiar irreality of such intuitions—that they have no physically objective basis in fact, but do have an undeniable influence on our assessments of types of behavior—you can rationally choose which moral intuitions to give assent to and obey, and you can choose which ones to ignore or repurpose. You can choose to adopt certain courses of action as a general rule and then harness the power of moral intuition to reinforce them. You can, in effect, choose your duties.
Here is an example. I know a person who engages in environmental struggle. At the moment he is trying to put a halt to a real estate development that would destroy many beautiful trees and would cause harm to nearby neighborhoods. It has been a long slog with a few victories and many defeats. At times he becomes quite discouraged. But he continues, partly because he is stubborn and partly because he feels a sense of duty or obligation to do so. He is not a moral realist. He recognizes that morality is socially constructed and that he is free ignore it. But he assents to the duty under which he finds himself.
He does so because he sees it as his dharma, a concept from Hinduism. One of the meanings of the Sanskrit word “dharma” is duty. This concept of duty, however, is not a narrow moral one, not a list of right things to do and wrong things to avoid. Rather it has a sense of acting in accord with the fundamental order of the universe, with what holds everything together. The concept includes duties, rights and laws, but also virtuous conduct in general.(1) It assumes, of course, that the universe has a fundamental order that has some relevance to human conduct.
This person chooses to continue in the struggle because he prefers to be the kind of person who assents to such duty. He adheres to the goodness ethic, to work for the good in all things.(2) Preventing harm to his neighborhood is an obvious good, and so is saving trees and wildlife habitat, especially in the face of global warming. He chooses to undertake a task that he has the skills to do and that increases his skills with practice. Enhancing useful skills is also an obvious good. He wants to have admirable character. He wants not just to be admired, but to be admirable, that is, to have character that people have good reasons to admire. Perhaps, he hopes, others will become motivated to work for the good as well, and such motivation would increase goodness. And he does it in order to strengthen his ability to persist in the good despite painful feelings of discouragement, anger and fear.
He wants to become the kind of person who does good things as an expression of who he is rather than one who merely obeys a set of rules. The importance of good character is that not only can others rely on a person of such character but that the person can rely on himself or herself as well. In this case he does not have to question continually whether to persist in the often unpleasant struggle, but can spend his energy actually doing so. He is virtuous in an Aristotelian sense: he has skills (arete); he has enough practical wisdom to put them to good use (phronesis); and in so doing he experiences a kind of fulfillment (eudaimonia).(3)
He is a bit of an existentialist in that he chooses to create himself as the person he wishes to be. And he is a bit of a mystic in that he believes that the universe does, in fact, have a fundamental order. It has an inner unity with a drive toward increased richness of satisfaction. He finds himself an integral part of the living being that is the cosmos as a whole. If he did not follow his dharma he would not be fully himself, and both he and the universe would be poorer.
Duty in the sense of societal restrictions is to be questioned. Duty as dharma, as acting in harmony with the will of the Whole, is to be discerned and embraced.
(1) Wikipedia, “Dharma.”
(2) Meacham, How To Be An Excellent Human, pp. 14-17, and Meacham, “The Goodness Ethic.”
(3) Hursthouse, “Virtue Ethics.”
Hursthouse, Rosalind. “Virtue Ethics”. The Stanford Encyclopedia of Philosophy (Fall 2013 Edition), Edward N. Zalta (ed.). Online publication http://plato.stanford.edu/archives/fall2013/entries/ethics-virtue/ as of 6 August 2016.
Meacham, Bill. How To Be An Excellent Human. Austin, Texas: Earth Harmony, 2013.
Meacham, Bill. “The Goodness Ethic.” Online publication http://bmeacham.com/whatswhat/GoodnessEthic.html.
Wikipedia. “Dharma.” Online publication https://en.wikipedia.org/wiki/Dharma as of 20 October 2016.