This chapter examines Henri Bergson’s account of intuition—about which, as he complained, “so much nonsense” had been written—as it is developed not just in “Introduction to Metaphysics”, but also in his later work. In contrasting relative and absolute knowledge thus, Bergson is taking sides with French philosophers such as Ravaisson, and distancing himself from Herbert Spencer, who expounded and promoted the influential doctrine of the Scottish philosopher William Hamilton, according to which all knowledge is relative. Intuition, and thus philosophy, is a kind of immediate knowledge that is independent of the generalising tendencies of language and conceptual thought. The chapter considers that theory is independent of practice, but Bergson argues that our theorising, from the ground up, is intrinsically practical and purposeful. Both intelligence and the inert matter with which it is made to function, Bergson argues, presuppose geometrical extension, but he considers extension as ex-tension, i.e. the relaxation of duration.