There's a lot of hand-wringing when Morgan catches up to Gavin and holds him in his sights. It's the usual thing: Carol and Ezekiel exhort him not to give into his violent urges and to spare his life, reminding him that this isn't the only way to do things and that men are still basically good at heart. (We've heard this speech before: Morgan himself has delivered it several times over the last two seasons.) The man hems and haws, and the whole thing is meant to echo Carl's words about designing a better, less sadistically violent future. Whether Morgan can still hold back or has forever gone too far is a test case for whether Rick will be able to do the same when the time comes for Negan.
But given the incessant clatter of machine guns that have been firing off without mercy for the last 45 minutes, bodies falling over and over without the slightest moral pause, this crisis of conscience feels a little disingenuous. We're now eight seasons into The Walking Dead, long enough that these back-and-forth questions about what is right and what is wrong in all-out-war have gotten pretty tiresome. We know that the basic theme of the show has always been the difference between living life and just surviving: it's constantly reminding us that, no matter how hard things get, there's always such thing as going too far. We don't need another speech about the value of human life and the importance of mercy. We've heard it already.