 For Maritain, all human enquiry has ‘being’ as its object; being, in other words, is the formal object of the intellect (Preface to Metaphysics, 1934 [1939: 25]). But ‘being’ can be grasped in different ways, and Maritain distinguishes, for example, between sensible being (“the object first attained by the human intellect”) and being as being (which is the object of metaphysics). The way in which he does so distinguishes him from several of the other leading twentieth-century Thomists, such as Gilson and Fabro (Contat 2008). It is because of this difference in object that Maritain distinguishes (as he notes in his epistemology and his philosophy of nature, discussed below) among the activities of the empirical scientist, the mathematician, the philosopher, the theologian, and the mystic.