I am not educated in literature, so I never heard of this before, but came across Empson's 7 types of ambiguity. David is a big fan of ambiguity, I believe. Literally and...uh ambiguously. I'm not going to elaborate, but below is the wiki link and the list.

http://en.wikipedia.org/wiki/Seven_Types_of_Ambiguity_%28Empson%29

1. The first type of ambiguity is the metaphor, that is, when two things are said to be alike which have different properties. This concept is similar to that of metaphysical conceit.

True humility is intelligent self-respect which keeps us from thinking too highly or too meanly of ourselves. It makes us mindful of the nobility God meant us to have. Yet it makes us modest by reminding us how far we have come short of what we can be.

ralph w. sockman

I've been thinking of a general theory of David Cook. I think my conclusion is that what he exhibits most of all is true humility.