La materia e il vuoto. Una nuova lettura della hyle tón gignomenón di Plotino

Plotinus’ theory of matter has appealed to serious scholars in the last twenty-five years or so, and the new book is a welcome contribution to the debate. It concentrates on the notion of void, an issue which is not extensively, let alone systematically, treated in the Enneads. A supplementary volume to the Rivista di cultura classica e medioevale, it ends with an adequate bibliography but lacks indices of any kind, which is a great pity indeed. The bibliography also lists some works on the modern conceptions of the void but omits a few papers referred to in the footnotes, such as those by D. J. Furley and D. Lehoux on Strato (p. 13, n. 14), and R. B. Todd on Cleomedes (p. 13, n. 16).

Mattei aims to show that on Plotinus’ account void is conceivable, even if it has no real existence. Furthermore, it can also be thought of as possessing some kind evidence; it is not a physical space deprived of matter, but a ‘spazio meta-fisico’ deprived of form. She also assumes that Plotinus’ argument runs at two levels, the one is explicit but failed, the other is implicit and difficult to discern but at the same time fruitful. The latter focuses on the void devoid of forms, comparing it to the concept of matter.

After a short introductory survey (11-19), both theoretical and historical, Mattei examines the passages where Plotinus seems to deny or affirm the existence of the void. These are: II 4.11.25-29; III 6.7.31-33; IV 3.20.24-27; IV 4.23.46-47; IV 5.2.12-13; IV 5.6.1-4, 14-16; V 1.9.20-21; V 3.9.13-15; V 8.4.27-29; VI 3.25.32-35; VI 4.2.7-9; VI 4.15.10-11. The account contains three approaches: to show that (1), in general, there are serious problems with the very nature of the void. The void cannot exist in nature, a supposition which is not proved but thought to be well-known. Here Plotinus may have been relying on Aristotle’s arguments in Physics IV 9. (2) It is impossible for the void to exist either in the intelligible or in the sensible world. Finally (3) atomistic ideas, though not recognised by Plotinus, lurk behind the discussion of many related issues, such as that of the continuum. She also thinks (28) that in the first three texts Plotinus refers to some intrinsic problems arising from a wholesale rejection of the void. As a consequence, she seems to allow for the possibility that void is a pure ens rationis, a place which is completely devoid of forms and therefore devoid of bodies as well. Its function resembles that of the universal receptacle in the Timaeus. At this point one might stress that we are entitled to speak about resemblance only, not about identity, for Plato’s χώρα or ὑποδοχή may have a metaphysical status very different from the one of an ens rationis. This metaphysical space is unlimited, immeasurable and without positive properties, just like Aristotle’s prime matter.¹ As for the relation between void and sensible matter,² she emphasises that Plotinus denied any role of a principle to matter (43).³ Thus matter becomes an inactive and indifferent instrument in the formation of physical objects. In this respect, it manifests the same characteristics as those the void displays in Aristotle (45). The properties of the matter of the sensibles (which is devoid of forms) thus come to characterise the void, which was originally treated as an entity devoid of matter. This is an important and striking thesis, said to be forced by the internal logic of the texts, but it may run against Plotinus’ intentions, as Mattei admits (45, 53).

Historically speaking, it may be true that Plotinus’ description of prime matter owes much to Aristotle’s analysis of void. However, one might raise two problems. The one concerns the extent to which we are allowed describe Plotinus’ notion in Aristotle’s terms. It is true that for Aristotle the void cannot be conceived of as a place devoid of bodies ( Physics IV 8, 214b28-31). But the reason is that place is not something to receive the bodies. Rather, it is the first immobile boundary of bodies (IV 4, 212a18-21). This notion is far from the one we read in the Timaeus, which is followed by Plotinus. In fact, Plotinus makes a distinction between the matter of physical things, which is a sheer potentiality, their extension and their place (II 4. 12. 1-13).⁴ Secondly, it is true that Plotinus conceives of matter in terms not involving space. For instance, we read that matter is unlimited οὐ κατὰ τὸ πόσον (II 4. 16. 10, though this implies only that matter is not extended). He also asserts that the unlimited ( ἄπειρον) is not something that implies space; it is not a spatial extension that cannot be traversed ( ἀδιεξίτητον, II 4. 7. 13-20).⁵ On the other hand, if we allow the metaphysical void to be described in much the same terms as those characteristic of prime matter, then we may face a new problem. If metaphysical void is something deprived not of bodies, but of forms, then how to account for the relation between this kind of void and the intelligible matter? Is there any relation between them? If we deprive void of any characteristic implying physical existence, and stick to a description in negative terms of a more general kind (bodies involve forms, but forms do not involve bodies), then it seems natural to ask about a possible link between void and intelligible matter. After all, geometrical bodies such as triangle and cube all have a certain formal aspect, which implies a substrate called intelligible matter. If metaphysical void is completely formless, what is the difference between the ways it links to the two kinds of matter? Thus it might be unwise to insist on such a relationship, for mathematical objects are of a status highly different from physical objects. Accepting such a relationship we may be forced to bring the matter of the sensibles and intelligible matter to the same level of existence.

The book is handsome and practically free of typos. The only slip I have found worth mentioning is on p. 53 where the reference to Aristotle’s ‘ Phys. IV 9, 20 ss’ is not as clear as it should be.

In sum, the book is a welcome contribution to the discussion of a crucial issue in Plotinus’ philosophy. It raises important questions and urges the reader to consider them over and over again.

Notes

1. Mattei refers to Physics IV 7, 214a13 ff, but I think it would have been better to refer to Metaphysics VII 3, which explicitly anticipates some of the problems Plotinus is struggling with. In 1029a22-27 we read that the ultimate substrate (that is the prime matter) is free from all sorts of qualifications. It is not even a ‘something’ ( τι). As predications can only be made of forms/formal aspects, we cannot say anything about prime matter, even negations can be made of it only incidentally. And the notion of matter as not-being can also be traced back to the Sophist, as has been shown by D. O’Brien, ‘La matière chez Plotin: son origine, sa nature’, Phronesis 44(1999), 45-72.

2. Although Mattei speaks about ‘materia sensibile’ throughout, it may be better to avoid possible misunderstanding and render the expression ὑλὴ νοητή as ‘matter of the sensibles’.

3. Mattei assumes that Plotinus’ denial is a new development in the history of Western philosophy. Let me make two small points. When Aristotle is talking about matter as a principle, there may be good reason to assume that he is thinking of proximate matter, not prime. He has relatively few things to say about prime matter in general. Moreover, if one is ready to accept the approaches that give a detailed and systematic picture of Plato’s ‘unwritten doctrines’, one may be justified in thinking of the indefinite dyad as a principle, although completely inactive and unformed.

4. The threefold distinction may be an upshot of Aristotle’s critique of Plato’s conception, as has been shown by K. Algra, Concepts of Space in Greek Thought, Leiden: E. J. Brill, 1995, 119-120.

5. Compare the analysis in H. Benz, ‘Materie und Wahrnehmung in der Philosophie Plotins. Würzburg: Königshausen & Neumann, 1990, 129-133, 156-178, esp. 165. Mattei includes the book in her bibliography but does not seem to discuss it in the relevant chapters (ch.2-3).