Wally W. answered • 04/01/22
MA Philosophy Grad and Experienced College Tutor
According to Ross's ethical theory, we have a certain number of "prima facie duties" that together dictate what we should or shouldn't do. For example, there are duties of fidelity (the duty to keep your promises), of beneficence (the duty to create good things, to make things better), of non-maleficence (the duty to avoid causing harm), and others.
Ross differs from a few other moral philosophers in how he thinks about duties. In particular, he doesn't think that something's being your duty guarantees you have to do it. For Ross, having a duty to do something definitely gives you some reason to do it -- but, there could be a stronger reason to do something else. That's why he calls them "prima facie duties". Prima facie is latin for "on the first impression", or "at first glance". A prima facie duty, then, is a duty that you have at first glance, barring other considerations.
So take an example of a moral dilemma: you've arranged to meet your friend for lunch, but on your way over, you see someone drowning. You could totally jump in and rescue them, but it'd make you late to your meeting. What should you do?
According to Ross, it makes perfect sense to say that you have a duty to your friend and a duty to the drowning person -- it's just that you should save the drowning person because that duty is stronger, more urgent.
In other words, you have several duties vying for dominance here: (1) a duty of beneficence and non-maleficence to the drowning person (for whom you could bring about great benefit and relief from harm by saving their life), and (2) a duty of fidelity to your friend (to whom you've made a promise to meet them). Since the stakes are so much higher if you fail to do your duty to the stranger, that prima facie duty wins, and it would be wrong for you to run along and get to your lunch date on time.
