How to measure the velocity of a thought: "I am trying a method of my own invention: I shoot a perfectly empty thought through all the others, and because it has no content of its own, it reveals the furtive outlines—which are stable in the empty one—of the contents of the others. That ... Speedometer is my companion on solitary walks and the only one who knows all my secrets." —César Aira (as translated by Katherine Silver), The Literary Conference