So the problem (Elbow asked for "someone [who] would try using it [the doubting game] on my argument to see what we can learn) that we are to solve is to find the error in his epistemology. His epistemology is that knowledge is available either through doubt or through belief. The easiest attack is to divide and conquer.

Epistemology based on doubt goes back to Descartes and Plato. For Plato, the socratic method exposed all faulty systems to continual definition, rendering most of these systems and statements either empty or contradictory. Of course, Plato's writing was never exposed to the same fire. As Jasper Neel points out in Plato, Derrida, and Writing, Plato steals writing from the rest of us and hogs it for himself... more later