 Philosophical reflection on being begins with the intuition of being, and Maritain insists that one needs this “eidetic” intuition for any genuine metaphysical knowledge to be possible. The intuition of being that lies at the root of metaphysical enquiry is not that of “the vague being of common sense” (see Preface to Metaphysics, 1934 [1939: 78]), but an “intellectual intuition” (Existence and the Existent, 1947 [1948: 28]) or grasp of “the act of existing”. (This emphasis by Maritain on the intuition of being goes beyond what we find in Aquinas—some have argued that it is altogether foreign to him [Wippel 2014, Knasas 1992]—and arguably reflects Bergson’s account of the intuition of duration. As noted earlier, some have argued that Maritain’s debt to Bergson overall is much greater than he himself held [Gwozdz 2010].) 