It's been a crazy few days for Jon Snow. First, he gets assassinated by his own men. Then he comes back from the dead. After that he has to execute the men who killed him. Who could blame the guy for deciding, as he did at the end of Sunday's episode, that he'd had enough of the Night's Watch, walking away from the Wall seemingly for good?
The episode was titled "Oathbreaker" after Snow's decision, which brings us to an interesting philosophical question: Did Jon Snow break his Night's Watch oaths by abandoning the brotherhood? For reference's sake, here's the show's version of that oath:
Night gathers, and now my watch begins. It shall not end until my death. I shall take no wife, hold no lands, father no children. I shall wear no crowns and win no glory. I shall live and die at my post. I am the sword in the darkness. I am the watcher on the walls. I am the shield that guards the realms of men. I pledge my life and honor to the Night's Watch, for this night and all the nights to come.
Most relevant to our interests is the "shall not end until my death" part. As Kit Harington was very fond of reminding us during Thrones' off-season, Jon Snow definitely died when he was stabbed by those Night's Watch mutineers. But in most understandings of death, the fact that you can't come back is a pretty fundamental part. If a death is not permanent, does it still count as a death?
According to the Stanford Encyclopedia of Philosophy, scholars didn't begin to debate the exact definition of death in earnest until the 20th century. In the real medieval world, medical care was such that various gradations of death were a moot point: If your brain died, your heart died shortly thereafter, and vice versa. (Of course, this same lack of strict definitions meant that people were sometimes buried when they were not yet dead, a particular fear in the Victorian era.) Today, the philosophical debate has real-world implications for the field of medical ethics. If death is the loss of human consciousness, is someone in a persistent vegetative state dead? If death is the loss of some theoretical thing we'll call "personhood," is someone in the advanced stages of dementia dead? And if death is simply the end of cardiac function, has someone who's been revived after their heart actually stops back from the dead?
If so, that's the clearest possible model for Jon Snow, who was brought back after being dead roughly 24 hours — which is nothing compared to this Russian grandmother. The bad news for him, though, is that the Night's Watch vow is best understood as a verbal contract, and most modern legal definitions of death specify that it must in fact be permanent. As Duhaime's Law Dictionary puts it, death is the "irreversible cessation of circulatory and respiratory functions and of all functions of the entire brain, including the brain stem." The norms of Westeros aren't clear, but in the present world, if you come back from the dead, by definition, you weren't really dead.
And we don't even have to get that pedantic about it. The Night's Watch, whose whole raison d'être is battling ice zombies, know they're living in a fantasy world, and thus have constructed a clever workaround against anyone who might try to use the "die, then come back" loophole for getting out of their vows. It's there in the last sentence: "I pledge my life and honor to the Night's Watch, for this night and all the nights to come." So there you have it — as long as the world still exists, the men of the Night's Watch are sworn to defend it, no matter how many times they've died.
Ultimately, though, since the men of the Night's Watch seem to regard Snow as something closer to a god right now, it's unlikely that any barracks lawyer is about to ride up and punish him for failing to read the fine print. But it is a warning to anyone who'd like to follow in his footsteps: Strange women cutting hair and saying magic words is no basis for getting out of your vows!