What does it mean for a duty to be a prima facie duty?
Moral philosopher W.D. Ross gives the descriptor of "prima facie" (at first glance, or "foremost") to several duties that help us make our daily choices on what we ought or ought not to do. It is basically the moral consideration that we weigh upon the thins that we do everyday. It also has to do with the importance that we place upon ethical behaviors. A common example is keeping a secret. The proper thing to do is to keep the secret that you promised to keep. This could be overridden by a stronger motivation to tell the secret but, the prima facie thing to do would be to comply with the promise.
There are more duties that we consider, even when we do not purposefully tap on them to bring them out right away in our minds. In the example about keeping a secret the two prima facie duties that are involved could be self-improvement and justice.
Self improvement entails the want to achieve betterment of behavior or action by doing what is proper to do. Notice that this is basically the same as doing good "for goodness's sake", that is, for the sake of doing what is right to do simply because it is the right thing to do.
Justice is referred to as
distribution of pleasure or happiness...that is not in accord with the merit of the person concerned.
Therefore, the FAIR thing to do is to keep the secret because if the secret is told it would be unfair for the person who told the secret in confidence.
Other prima facie duties include reparations (the need to pay for mistakes we have done onto others), care and beneficence, which could also apply to the act of keeping a secret or a promise as we said that we would.