This is from an email conversation with my friend Adam Roberts about a recent post of his. N.B.: We’re in medias res here. 

It doesn’t take long to get into intractable difficulties, does it? I don’t know the solution to any of them, of course, but the most obvious one goes something like this, I think:

Though Milton’s God is not always identical with what I would call the Christian God, I do believe he’s in the general vicinity when he says that he made all the rational creatures “Sufficient to have stood, though free to fall.” This suggests that obedience can only be valuable and beautiful when a creature possesses the moral imagination to consider and reject disobedience. You could even say that this is what rational freedom is: the exercise of moral imagination. A creature cannot be virtuous unless it can imagine being vicious.

And imagining sin is not the same as doing it, which is to say that there is some distinction between imagination and will; and that in turn means (as everyone who reflects on these matters ultimately realizes) is it difficult to say when the Fall actually happens, for angels or humans. It’s the crossing of this invisible line from imagining something to willing it. For Milton’s Satan it seems to have happened at the moment that he “thought himself impaired.” (Presumably something very similar happens to all the other rebel angels — if they fell only because they were tempted by Lucifer, then presumably God would extend the same grace to them that he extends to humans.)

So:

1. All rational creatures have both the strength to stand and the freedom to fall; 
2. Their moral imagination allows them to understand what falling might be; 
3. Satan and the other rebel angels move on their own from imagining to willing disobedience; 
4. Adam and Eve also make that move, but as a result of external temptation; 
5. Therefore, God extends grace to Adam and Eve but not to the angels. 

I think that’s coherent, if not necessarily convincing; though of course it leaves a thousand other questions unanswered (e.g. Milton gets himself into an enormous amount of trouble, I think, by having Eve so openly chafe against the authority of Adam).

But to pull back from this scene for a moment: The various scenarios you outline in a previous email — your delineation of (a) kinds created (b) numbers created (c) proportions of the Obedient and the Disobedient — confine themselves to this world, and we don’t know whether this world is the only one populated by rational creatures with moral imagination. So CSL imagines a whole solar system of such creatures and suggests that our world is the only fallen one. What if we extend that to the whole galaxy, the whole universe? Setting aside Fermi’s Paradox, this could be an unimaginably vast universe absolutely full of rational creatures praising their Creator and rejoicing in their obedience to Him … while we alone are the broken ones. Earth, then, becomes the cosmic version of the tiny closet in which the one poor child suffers in Omelas.