One of the ways in which St Thomas distinguished the speculative sciences from each other was through the kinds of being they considered. Thus, whilst natural philosophy considered material being and mathematics quantified being, metaphysics, uniquely, considered being insofar as it was being (In Meta. IV, # 530). This way of characterising metaphysics, however, inevitably led to further questions. For instance, how does one acquire the requisite notion of being? Does such a notion, which henceforth we can call the metaphysical notion of being, differ from being as first known? Once acquired how might this notion be employed in metaphysics? What use, if any, might be made of it in theology? Certainly these are difficult questions, but it is the challenge of exploring them that motivates this collection of essays which Christopher M. Cullen S.J. and Franklin T. Harkins have edited.
The editors divide the collection into three sections. The first, which is further divided into five chapters, focuses on the acquisition of the metaphysical notion of being. Wippel's essay in chapter one sets the tone. Broadly speaking it turns on three points. First, that being as first known is distinct from the metaphysical notion of being. Second, that the judgment of existence is employed in the formation of both notions. Third, that prior knowledge of the existence of positively immaterial being is not required to establish the metaphysical notion of being.
This third claim has proved particularly contentious, however. Suppose x is true of y in virtue of z. The truth of ‘y is x’ will hold regardless of whether we also know its truth is a consequence of z. Applied to Wippel's analysis then, ‘being is not material’ may be true in virtue of the fact that positively immaterial being exists (God or the rational soul) regardless of whether a given philosopher has demonstrated such at this stage of the order of discovery. Yet if metaphysics is a demonstrative science, its premises and the middle terms they contain must be better known than their conclusions (Post Analyt. 71b 20). But how can this criterion be satisfied if the existence of positively immaterial being has not been demonstrated prior to the judgment of separation?
Te Velde and Knasas's essays move towards more idealistic notions of being (pp. 58, 73). Thus Te Velde insists that, ‘metaphysical realism…cannot exist without a certain form of idealism of the first notion of being’ (pp. 58–59). This first notion of being is ‘the concept which allows our intellect to conceive and to assert…a mind-independent world’ (p. 59), a concept which crucially is ‘prior to any concrete specimen of knowledge we acquire’ (p. 49). Yet if the concept of being has neither remote nor proximate origin in extra-mental reality, nor is an imaginative rearrangement of concepts which themselves enjoy such origins, then it will have a weaker epistemic status in Aquinas's metaphysics than even the concept of a chimera. How can it, therefore, deliver proper knowledge of ens commune, its properties, and its causes?
Knasas's essay argues that ‘sensation prompts the intellect to conceive a wider sense of being than ens mobile’ (p. 78), a sense which allows for the development of metaphysics. Yet whilst it is certainly true that Aquinas distinguished the immaterial reception of forms in sensation from the material reception of those same forms in alteration (ST 1a Q78 art. 3), it is difficult to see how this contrast delivers the broader sense of being Knasas seeks, much less a foundation for the development of metaphysics. Neither the sensible form received immaterially nor the sense power which receives that form subsists. Therefore in becoming aware of sensation one does not discover hitherto unknown subsistent immaterial things which justify considering being insofar as it is being rather than merely as mobile. At best one might consider the immaterially received sensible form as a being of reason. Yet to use it in an attempt to establish the metaphysical notion of being would require that its character as a being of reason be recognised as essential to it. So understood any subsequent attempt to incorporate it into a notion of being would inevitably entail a move towards an idealistic notion of being.
The second section, which is divided into four chapters, applies the metaphysical notion of being to controverted problems in philosophy. Doolan's and Long's contributions are particularly striking. Doolan analyses the division of ens commune into the categories and argues that those categories are both exhaustive and suppositionally necessary (pp. 137, 140). Their suppositional necessity deserves further comment. Roughly we might say that a would be suppositionally necessary for b if b entails necessarily a, but a does not entail necessarily b. So understood Doolan's view amounts to the claim that God's desire to create the best world entails that necessarily all the categories will be instantiated in that world (p. 141). In effect that if all the categories were not instantiated, the resulting world could not be the best world. Why should that be the case though? God is subsistent being. Therefore the best world will surely be one populated by subsistent beings, or substances, which in virtue of subsisting reflect God's goodness in creation, regardless of whether they also possess accidents. More needs to be done to show that the accidental categories of being must be instantiated.
Long's essay explores the analogy of being. He argues that ‘causal reasoning to God’ (p. 192) and ‘the doctrine of participation’ (ibid.) each logically presuppose the analogy of being. Whilst these claims are to be applauded, one might still take issue with some of the reasoning used to support them. For instance, Long appears to understand being existentially. He tells us that ‘being is real’ (p. 175) and that its ‘real character’ (ibid.) is the foundation for the distinction between being and non-being (ibid.). Furthermore, that real character entails that the principle of non-contradiction is a metaphysical and not merely logical principle (ibid.).
That Long intends being's reality to be understood existentially follows upon the examples used to explain it. Thus Long remarks, ‘even had creation never occurred, it would be true that God's nature is not a created nature by virtue of the reality of the divine nature itself’ (ibid.). However, God exists necessarily; God's nature is God's being. Hence the reality of God's nature must imply its existence. Further, he writes, ‘one's sister is by virtue of her real humanity not a square root’ (ibid.). Yet in order for one's putative sister to be really related as sister, at some point her real humanity must have existed so that it could be the subject of such a real relation. In both cases then ‘real’ and ‘reality’ imply existence. Moreover, since these texts explain the reality of being, then the reality of being will also imply existence. It is not clear, though, that Aquinas always understood being existentially. For example, in remarks in his Metaphysics-Commentary Aquinas linked the principle of non-contradiction to being known through the understanding of indivisibles (In Meta. IV, # 605). Yet ‘the understanding of indivisibles’ and ‘simple apprehension’ each name the first act of the intellect. That act is not a judgment and therefore manifestly has no existential import. Nor need one understand being existentially in order to distinguish it from non-being: being can be, non-being cannot. At the very least, further explanation is required to explain why being must be existential.
The third section is divided into four chapters and explores the role of metaphysics in central theological topics (p. 5). Limitation of space prevents discussion of the essays, but they are all interesting and insightful, as is the collection as a whole. Its main weakness is a consequence of what it lacks: an essay on the natural philosophy approach to metaphysics in section one and an essay on Christ's being in section three. Otherwise the collection does a fine job of exhibiting the speculative power of contemporary Thomism.