I remember in my fiction class we talked about how many authors subscribed to this belief that we, as writers and as people, only really have one story. That every work we do just contributes to that greater single story that we’re trying to tell.
I feel like Milton’s works support this — we see similar arguments from all his works coalescing and conversing in Paradise Lost. That’s what I was thinking about when Professor Campbell said that we saw the same argument from the divorce tracts arise again in Book 8. I do wonder if Milton thought the same thing and that’s why he spent his whole life trying to write Paradise Lost — because he knew that was his “story.” The one story that all of the other treatises and poems were aspiring toward.