One after another, I should like to explore the many paths that lead to the heart of these challenging tests. As Deleuze has said to me, however, this metaphor is misleading: there is no heart, but only a problem-that is, a distribution of notable points; there is no center but always decenterings, series, from one to another, with the limp of a presence and an absence-of an excess, of a deficiency. Abandon the circle, a faulty principle of return; abandon our tendency to organize everything into a sphere. All things return on the straight and narrow, by way of a straight and labyrinthine line.