Deutsch also heavily argues for explanations as first-class existence on the level of matter. For him, predictions are simply a practical concern. I still fondly remember his dialogue between Socrates and Apollo in dream, where he convincingly makes the point that even there he can find true knowledge about the world.
Deutsch really argues for Popper's "conjecture and refutation" model of science (or as he renamed it, "conjecture and criticism") and one of the great points he makes is that both those processes can be done entirely in the mind. Physical evidence may be necessary for some kinds of criticism, but sometimes reason alone can produce useful criticism.
I also like his point (in conversation with Sean Carroll) that we have rigorous proof that the notion of explanation can't be formalized, yet explanation is at the core of the scientific endeavor anyway.
