Jim Everett and M Crockett in Scientific American:
The inhabitants of Westeros and Essos repeatedly face versions of a classic moral dilemma: When is it morally permissible to cause harm in order to prevent further suffering? Philosophers have debated moral dilemmas like this for over a thousand years. “Utilitarian” theories say that all that matters for morality is maximizing good consequences for everyone overall, while “deontological” theories say that some actions are just wrong, even if they have good consequences. The tension between deontological and utilitarian ethics can be seen in the origin story of Jaime Lannister’s sobriquet “Kingslayer”: When the “Mad King” Aerys Targaryen orders for the entire city to be burned, massacring the many thousands of citizens that live there, Jaime violates his sacred oath to protect and serve his lord and instead slits the king’s throat. Utilitarian theories would praise Jaime’s decision to kill the Mad King, because it saves many thousands of lives, while deontological theories would prohibit killing one to save many others.
When psychologists study utilitarianism, they focus almost exclusively on sacrificial dilemmas like the one Jaime faced. This is what we call“instrumental harm”—asking people whether, for example, they think it’s morally acceptable to harvest a healthy person’s organs to save the life of a dying patient. Game of Thrones is replete with such examples: for instance, when Olenna Tyrell organizes the murder of Joffrey Baratheon; when Daenerys invades Slaver’s Bay to free the slaves, and when Jon Snow, in the series finale, murders Daenarys to prevent her from killing more innocent people. As Tyrion presciently remarks of Daenarys in the final episode, “She believes her destiny is to build a better world…. Wouldn’t you kill who stood between you and paradise?” This could well be a utilitarian motto: to create paradise for all on earth, some might need to suffer.
More here.