3. Principal Contributions
3.1 Metaphysics
Although Maritain did not produce a text that provided a comprehensive statement of his metaphysics, his major contributions to the area are found in Sept leçons sur l'être et les premiers principes de la raison spéculative [A Preface to Metaphysics: Seven Lectures on Being] (1934), the Court traité de l'existence et de l'existant [Existence and the Existent] (1947) , and in De Bergson à Thomas d'Aquin, essais de métaphysique et de morale (1944). Discussion of his metaphysics are also found in other works, such as The Degrees of Knowledge, The Range of Reason, Science and Wisdom, and Ransoming the Time.
As one might expect, Maritain's metaphysics follows in the tradition of that of St Thomas Aquinas, but it is far from a summary or restatement of Aquinas's views. In general, Maritain sees his task — and the task of Thomism in general — as being "to renovate" Aquinas's thought, "a task whose novelty may well be greater than [Thomists] themselves realise" (Preface to Metaphysics, pp. 12-13).
Following Aquinas, Maritain holds that metaphysics deals with being as being (ens inquantum ens), i.e., it "investigates the first principles of things and their highest causes" (Preface to Metaphysics, p. 27). And Maritain also holds that there are certain fundamental metaphysical questions to which Aquinas's responses are largely correct, though they may not be complete as they stand. Maritain adopts, against John Duns Scotus, Aquinas's general position on analogy, being, and on the need for analogical terms and concepts. Again, in answer to the problem of unity and plurality — e.g., how can a thing be individual and distinct and yet a member of a class of things of the same kind? — Maritain follows Aquinas: that we have to distinguish what a thing is (its nature or essence, which it shares with things of the same kind), from the fact that it is (i.e., that it has its own 'act of existing'). When it comes to the analysis of the nature and the unity of sensible beings, including human beings, Maritain employs Aquinas's distinction between the form and the matter of a thing; nature or essence reflects the form, whereas the individuality is determined by the matter.
Maritain's distinctive contribution is not, however, to the details of Thomistic metaphysics, but to bringing it into relation with modern science and philosophy, and to explaining its foundations.
For Maritain, all human enquiry has 'being' as its object; being, in other words, is the formal object of the intellect (Preface to Metaphysics, p. 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). It is because of this difference in object that he 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.
Metaphysical enquiry — the enquiry into being as being — is, Maritain says, a mystery because, for example, it is something that is too rich or 'pregnant with intelligibility' (Preface to Metaphysics, p. 4). Nevertheless, the mystery of being is an "intelligible mystery" (Preface to Metaphysics, p. 83), and Maritain holds that, unless one does metaphysics, one cannot be a philosopher; "a philosopher is not a philosopher unless he is a metaphysician" (Existence and the Existent, p. 29).
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 "the vague being of common sense" (see Preface to Metaphysics, p. 78), but an "intellectual intuition" (Existence and the Existent, p. 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 — and arguably reflects Bergson's account of the intuition of duration.)
This intuition of being "is a perception direct and immediate … . It is a very simple sight, superior to any discursive reasoning or demonstration [… of] a reality which it touches and which takes hold of it" (Preface to Metaphysics, pp. 50-51); it is, Maritain says, an awareness of the reality of one's being — one which is decisive and has a dominant character. This view of intuition is not, then, that of a hunch or quick insight; neither is it (Maritain continues) the same as Bergson's. It has an intellectual character, is a grasp of something that is intelligible, and requires "a certain level of intellectual spirituality" (ibid., p. 49). Interestingly, Maritain claims that this intuition of being is something which escaped Kant (ibid., p. 48) and many subsequent philosophers until, perhaps, the arrival of the existentailists.
There are approaches that one may take in order to acquire this grasp or intuition, but there is no method that one may follow that produces it. This grasp may, for example, be acquired by focusing on something real and then reflecting on what lies behind it. Thus, this "eidetic intuition" or "ideating visualisation" (ibid., p. 58) is one where we "look … reality … in the face", in which "reality [is] stripped of its real existence outside the mind" and discloses "the conditions of … an existence of intelligibility in act" (ibid., p. 58). This metaphysical intuition is, then, an "ideating intuition" of things in the perspective of their "intelligible values," rather than in terms of the actual conditions of their "contingence and singularity" (Science and Wisdom, p. 108).
Also distinctive in Maritain's account of metaphysics is the emphasis on "the act of existing." It is because of this that Maritain has been called an 'existentialist'; indeed, his Existence and the Existent, is subtitled "an essay on Christian existentialism," and he describes his view as an "existential intellectualism" (Existence and the Existent, p. 70). Maritain believes that such an emphasis is characteristic of any consistent Thomism; "What distinguishes authentic Thomism … is precisely the primacy which [it] accords to existence and the intuition of existential being" (ibid., p. 12). This 'existentialism,' however, is quite distinct from the existentialisms of Kierkegaard, Gabriel Marcel, or Jean-Paul Sartre. An "authentic existentialism," Maritain writes, "affirm[s] the primacy of existence, but as implying and preserving essences or natures, and as manifesting the supreme victory of the intellect and intelligibility" (ibid., p. 13). It stands against the position of his contemporaries who abandoned talk of natures or essences or of their intelligibility, but also against those who imagine that essences were created and then came to exist. (For Maritain, essences do not preexist existence; essences might be better seen as "capacities to exist" [ibid., p. 34].)
As one has the intuition of being and pursues this investigation into being, one is led into the traditional questions of metaphysics and natural theology. There are, Maritain holds, four basic principles of metaphysics: the principles of identity, of sufficient reason, of efficient causality, and of finality (i.e., every agent acts for an end). Though the truth or the applicability of these principles does not admit of direct proof, they are consistently confirmed by experience and, Maritain holds, cannot be denied without contradiction (Preface to Metaphysics, p. 90).
Metaphysics, then, properly includes an investigation into the cause of being — i.e., God, in whom the act of existing is subsistent. Since Maritain holds that being is something that is grasped through intuition, one is not surprised to see that he will argue that one can attain knowledge of the existence of God not only through the Thomistic five ways, but also through intuition. (This is discussed in 'Natural Theology and Philosophy of Religion,' below.)