Bryn Mawr Classical Review

Bryn Mawr Classical Review 2011.04.42

Marije Martijn, Proclus on Nature: Philosophy of Nature and Its Methods in Proclus' Commentary on Plato's Timaeus. Philosophia antiqua 121.   Leiden/Boston:  Brill, 2010.  Pp. ix, 360.  ISBN 9789004181915.  $179.00.  

Reviewed by Dirk Baltzly, Monash University (Australia) and Institute for Advanced Study (Princeton) (


The commentary form does not facilitate the communication of a synoptic picture of Proclus’ own philosophy of the natural world, since Plato’s text sets the agenda for exposition. Hence scholars of late antique philosophy will be very grateful for the synthesis that Marije Martijn presents in this splendid new book on the subject. Philosophers who concentrate on Plato’s Timaeus itself, rather than its later reception, can also benefit from this book. It must be said, however, that readers who have no acquaintance with Proclus’ philosophy will find this hard going. This is not an introductory book. It is, however, rich in erudition, philosophically rigorous, and highly original. In my view, Martijn’s first book announces her as a name to watch in the rapidly expanding field of late antique philosophy.

According to the neoplatonists, every work by Plato (or Aristotle) has a theme or skopos that forms its subject matter. The themes of the different dialogues each find their place in the Iamblichean reading order which, in turn, facilitates the ascent of the soul through the various gradations of the virtues. Proclus tells us at the beginning of his commentary that the theme of the Timaeus is a specifically Platonic form of natural philosophy or physiologia. What makes is specifically Platonic is that it goes beyond the mere study of matter and material causes and beyond the study of form immanent in matter. Such things are mere auxiliary causes or synaitia. Platonic physiologia follows the (putatively) Pythagorean practice of studying these as subordinate to transcendent efficient, formal and final causes (in Tim. I 2.29-3.13). But the efficient, formal and final causes of the visible cosmos include the Demiurge, the Autozôion that serves as his paradigm, and of course the Good. These transcendent causes, however, are all gods on the neoplatonists’ way of looking at things. So what then becomes of the distinction between Platonic physiologia and theologia? Or, to put the same question slightly differently, what is the relationship between the Parmenides, which is expressly identified as a theological work by the neoplatonists, and the Timaeus?

In the only other book dedicated exclusively to the study of Proclus’ Timaeus Commentary, Lernould argued that the answer to this question was, ‘Not a great deal.’1 In Martijn’s view, this is a hasty judgement, arrived at as a result of concentrating on the differences between Being and Becoming in Proclus’ philosophy. Her alternative strategy is to look at the continuities between the transcendent causes of the cosmos, on the one hand, and the various ranks of beings that they generate within that cosmos on the other. This insistence on the continuity between the sensible and intelligible realms is the controlling theme in Martijn’s book.

Two facts about later neoplatonism suggest in advance that Martijn’s strategy will be a winning one. First, there is the emphasis that Proclus places on the necessity of intermediate stages (mesa) in emanation (I 209.13; I 412.28; II 45.16, III 107.32), thus insuring that there are no sharp ‘breaks’ in the descent from transcendent causes to sensible effects. Second, there is the ubiquity of the principle that ‘all things are in all’ but in a mode of being appropriate to each (I 8.16; II 26.24; II 231.29). Thus the gods that cause the cosmos are also present in the cosmos, albeit in a different mode of being. The ontological continuity of procession assures us of the possibility of a corresponding continuity of methods for grasping the divine causes of the cosmos. Martijn’s book investigates this variety of more or less theological ways of pursuing physiologia in Proclus’ Timaeus Commentary.

Chapter 2 poses the question, ‘What is physis according to Proclus?’ Proclus himself dedicates two pages to the question of Plato’s view of nature. The nature of Nature, understood as an origin of motion, was a well established topic within the commentary tradition.2 Martijn argues that Proclus diverged from Plotinus in not identifying physis with the lowest stages of the hypostasis soul (cf. Enn. IV.4.13, 3-4). Her key text is in Tim. I 10.16-20. Nature is higher than the things that come after it by virtue of possessing their logoi or rational-forming principles and by virtue of giving them life. On the other hand, it is inferior to soul because it does not revert upon itself and because it, unlike soul, is divided in the realm of bodies. Martijn takes the conjunction of these claims to show that Nature is ‘irrationally rational’. It is rational in as much as it contains the logoi of the things that come after it. Yet it is irrational since it cannot revert upon itself due to its immanence in its effects (p. 45). Proclus wants to distinguish Nature from soul because he thinks of it exercising its causal influence within the things the cosmos in a different manner than soul does. Soul works from the outside – that is, while remaining essentially distinct from the bodies that it en-livens and moves – while nature works from the inside, as if it were an internal craftsman (in Parm. 794.2-8). It provides bodies with motion and life, serves as their proximate cause and sustains them (p. 60). Soul performs some of these roles too, but on Martijn’s view this overlap in function is compatible with their distinctness because each enjoys a different relation to the Demiurge.3

Martijn also argues that Nature exists not simply at a single level in Proclus’ ontology, but as a chain or series. Its primary manifestation is as the ‘nature of the universe’ that antecedently comprehends (prolambanein kat’ aitian) the causes of all celestial and sub-lunary things (p. 54). But in this way Nature both depends on higher modes of being for Nature (e.g. in the mind of the Demiurge) and gives rise to lower manifestations of nature (e.g. as the universal lunar nature that comprehends the species of things in the sub-lunary realm). Chapters 3 and 4 shift the discussion to Proclus’ different methodologies in the Timaeus Commentary. The big insight in Martijn’s book is that Proclus can employ different methods for presenting Platonic physiologia depending upon whether the links in the chain of Nature under investigation are higher or lower.

Chapter 3 takes up the striking fact that Proclus proceeds de more geometrico in Book II of his Commentary where he is discussing Timaeus 27d6-28a4. He refers to the accounts of Being and Becoming as definitions, while other claims are referred to as hypotheses, axioms or common notions. These are used in what Proclus regards as three ‘demonstrations’ for three conclusions: that the universe has its essence in Becoming, that it has an efficient cause (the Demiurge), and that it has a paradigmatic cause (the Autozôion). The existing literature on Proclus’ adoption of geometrical terminology has raised the question of why Proclus adopts this terminology. Does he do so simply to insist that there is a suitably ‘scientific and demonstrative’ way of talking about the nature of the sensible world? Or is ‘geometric’ here simply tantamount to ‘rigorously syllogistic’? In either case, why should Proclus not have preferred to characterise this method as dialectical, since its principal aim is to take us up from the cosmos to its true, intelligible and/or intellectual causes: the Paradigm and the Demiurge?

Martijn’s analysis of Proclus’ reasoning in Book II is extensive, covering about 95 pages. A short summary of her conclusion, however, is that Proclus chooses to compare this part of the Timaeus with geometric argumentation precisely because there is a sense in which physiologia must remain hypothetical. Just as Plato contrasts geometry with dialectic in the Republic by reference to whether each rises to an unhypothetical starting point (510b4-9), so too Proclus thinks that physiologia rises only as far as a hypothetical foundation, while theology goes beyond this to provide an unhypothetical foundation in the One. Moreover, doxa and perception are principal psychic powers through which physiologia takes place according to Proclus. Here too there is a parallel with the Republic’s characterisation of the difference between geometry and dialectic.

This chapter contains riches not only for scholars of Neoplatonism. The nature of dialectic in Plato’s Republic, and especially the notion of an unhypothetical archê, has been a source of controversy for years. It is customary to distinguish epistemological from ontological readings of the idea of an unhypothetical first principle. That is to say, is the unhypothetical first principle something grasped as the only epistemic alternative, since all others are self-refuting? Or is it unhypothetical in the sense that it is that upon which all potential objects of knowledge depend for their existence? Martijn’s discussion of Proclus is interesting because this is a reading of Plato’s philosophy in which ontological fundamentality coincides with epistemological fundamentality (cf. Plat. Theol. II 66.1–9, cited by Martijn on p. 136).

Chapter 4 takes up Proclus’ notion of the role of mathematics in Plato’s dialogue. The Timaeus conspicuously deploys mathematical concepts in the discussion of proportion among the four elements and in the harmonies in soul. Martijn again enters into existing debates about the ‘mathematisation of nature’ in Plato and in Proclus’ interpretation. I found this chapter the least satisfactory in the book. Martijn’s discussion of the causal role of various sorts of numbers in the work of Iamblichus, Syrianus and Proclus is very illuminating. However, she feels compelled to fit her interpretations of these ancient texts into a modern opposition between ‘realism’ and ‘instrumentalism’. Martijn’s characterisation of these modern views is not very nuanced and, in my view, does not add to the discussion. It seems to me that a better orienting framework for the material in this chapter would be the debate about causality in mathematical explanations of natural phenomena.4

The final substantive chapter of the book expands on Martijn’s earlier work on Proclus’ understanding of Timaeus’ claim (29b3-d3) to provide only a ‘likely account’ or eikôs logos in his discussion. Her reading of Proclus is complex and tightly argued. The key to understanding Proclus’ account of the eikôs logos passages lies in seeing it as a specific instance of the metaphysics of emanation. Just as the visible cosmos is itself an ontological image of the intelligible one, so too in the case of Timaeus’ account of the cosmos. Since emanation takes place through similarity, the written or spoken logos must stand in a relation of natural resemblance to the logoi or rational forming principles through which Nature makes the sensible cosmos. Martijn’s very original contribution in this regard is to recognise the parallel between the reversion of effects upon their causes and the way in which texts may be made more or less precise and accurate images of their subject matter by the art of the writer or speaker. Martijn illustrates this point by looking at the way that Timaeus (at least on Proclus’ understanding) tailors the methods through which he communicates physiologia depending upon the phase in the chain of Nature that he is discussing. So the geometrical method of exposition discussed in Chapter III makes for a better image of the higher reaches of Nature located within the Demiurge, while the emphasis on proportion and number among the elements is a superior means for crafting an image of Nature at the level of the visible universe. Thus Chapter V draws together what has gone before into a satisfying package.

The book includes 15 pages of bibliography, a subject index, and an index locorum. As with all the recent volumes in the Philosophia Antiqua series, the production is very professional: thick paper, good binding, ample margins. But, then again, for this price, you’d expect nothing less!


1.   Lernould, A. (2001). Physique et Théologie: lecture du Timée de Platon par Proclus. Pas-de-Calais, Presses Universitaires du Septentrion.
2.   Sorabji, R. (2004). The Philosophy of the Commentators 200-600AD, vol. 2: Physics, pp. 33-59.
3.   I 298.25 appears to me to provide a distinction that Martijn could have made more use of. Soul ‘works in conjunction with’ the Demiurgic intellect (synergei men), while Nature merely ‘assists’ (hypergei de).
4.   Mancosu, P. (2001). ‘Mathematical Explanation: Problems and Prospects’, Topoi 20, 97-117.

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