I have a question about the interposition “fools that they are” in the following:
“Fools that they are, they never knew thy guiltless pride, thy true spirit.”
Using Google’s Ngram Viewer, I found other works in which this appears. Its meaning is clear, and I’ve seen similar constructions: “fool though he is,” for instance. But can anyone tell me what this (almost rhetorical) device is called, and also why “that” is used instead of one pronoun or another (or none at all)?