When C.S. Lewis reads St Augustine ...

It is not often that I take my topic from Pastor Weedon's blog, but one of his recent posts definitely caught my attention, quoting C.S. Lewis: 

I am saying only that the highest good of a creature must be creaturely—that is, derivative or reflective—good. In other words, as St. Augustine makes plain [De Civ. Dei, xii, cap. I], pride does not only go before a fall but is a fall—a fall of the creature’s attention from what is better, God, to what is worse, itself.—Business of Heaven, pp. 217, 218.

That could benefit from a little unpacking. 

It seems to start with the premise that our human nature is based on God's nature, which is grounded in the belief that we are "in God's image" -- that our best and highest comes from God. He calls this "creaturely good": it is derived from God's goodness so it is "derivative" good. It reflects God's goodness so it is "reflective good." If our best and highest comes from God, derives from God, reflects God -- then becoming over-impressed with ourselves (or anything else) constitutes a fall: we turn our attention from the better (God) to the lesser. 

I would add a few thoughts. First, that turning away from God to ourselves is a loss of grace. The "loss of grace" is not some other thing that God does to us as a consequence of falling away; the "loss of grace" is another way of describing the thing we are doing to ourselves when we turn away from God: we lose that connection. If we agree that our "best and highest" comes from God, we might also agree that our whole being comes from God, that our true nature comes from God. So that in turning away from God we lose our true nature.