1.

In the middle of Chapter 1, the author launches explicit criticism of those who should be ‘pitied for their small-mindedness because they are amazed at accidental things and think much of minor investigation’ (391a23–4). The example of ‘those who earnestly describe to us the nature of a single place or the layout of a single city or the site of a river or the beauty of a mountain’ (391a18–20) indicates that the author criticizes disciplines such as topography, geography and history. Karamanolis claims that the author targets ‘specialized sciences’ that ‘study a particular subject matter’, as opposed to philosophy that seeks to understand ‘the massive structures of the world that make it an ordered and harmonious whole’.Footnote ⁵ Even more generally, the author seems to be contrasting philosophy with non-philosophical disciplines;Footnote ⁶ after all, the aim of Chapter 1 is to elevate philosophy above all other intellectual enterprises.

Regardless of one’s understanding of the precise target of the author’s explicit criticism in the opening chapter, I suggest that the same passage also contains implicit criticism. The implicit criticism targets visions of philosophy which do not include contemplation of ‘the cosmos and the greatest things in the cosmos’ (391a25–6). These are visions of philosophy according to which (i) the universe is not a cosmos, in which (ii) there is nothing particularly grand or marvellous about this cosmos of ours, or else which teaches that (iii) people should not waste time with questions of the cosmos, its nature and its composition, but should rather focus on human affairs. Here the targets might be the Epicurean and possibly some Socratic schools of philosophy.

According to the Epicureans, the universe is not a single thing or structure but an infinite void that accommodates an infinite number of atoms in motion, some of which interlock to form huge structures that the Epicureans are content to call ‘worlds’ (κόσμοι). These structures are spontaneously generated, and they last over a period of time before disintegrating into smaller parts that may or may not enter into the constitution of other worlds. There is an infinite number of worlds, they come in different shapes, some contain stars and planets like ours, some do not, some are populated by living beings, some are not. Much like any other, this cosmos of ours came to be the way it is, without any purpose or guidance, and after a while it will change and ultimately cease to exist. There is nothing special or unique about it, nothing supernatural or divine, nothing to be glorified or extolled. This cosmos of ours and the phenomena in it should be studied only for the sake of, and to the extent they are, liberating us from the fear of gods, death and punishment. As Epicurus writes to Pythocles, ‘do not believe that there is any other goal to be achieved by the knowledge of meteorological phenomena, whether they are discussed in conjunction with physics in general or on their own, than freedom from disturbance.’Footnote ⁷

The Epicurean vision of philosophy and conception of the cosmos are clearly incompatible with our author’s, who maintains that philosophy ‘comprehends divine things with the divine eye of the soul and announces them to humans’ (θείῳ ψυχῆς ὄμματι τὰ θεῖα καταλαβομένη τοῖς τε ἀνθρώποις προφητεύουσα, 391a15–16) and invites the reader to ‘theologize’ about the greatest structures in the cosmos (θεολογῶμεν περὶ τούτων συμπάντων, 391b4). So, when the author dismisses those who are ‘unable to see the nobler things—I mean the cosmos and the greatest things in the cosmos’ (ἀθέατοι τῶν κρειττόνων εἶναι, κόσμου λέγω καὶ τῶν ἐν κόσμῳ μεγίστων, 391a25–6), it is not just wretched topographers, geographers, historians and other petty non-philosophers, but also—implicitly—philosophers like the Epicureans, who are unable to appreciate the cosmos and marvel at its majesty.

On the other hand, there is a Socratic vision of philosophy. According to a well-entrenched tradition, Socrates abandoned the study of nature at some point in his career and focussed all his efforts on the study of human affairs and conditions for a happy life. Aristotle himself is one of the main sources of this tradition. ‘Socrates was preoccupied with ethical matters’, Aristotle famously remarked, ‘not at all about the world of nature as a whole’.Footnote ⁸ This conception of philosophy was adopted by two relatively long-lived Socratic schools, the Cynics and the Cyrenaics, which disdained all metaphysics, natural philosophy and logic in favour of ethics. Diogenes Laertius wrote that the Cynics were content to ‘do away with the subjects of logic and physics and to devote their whole attention to ethics’Footnote ⁹ and that they ‘also dispensed with general education’.Footnote ¹⁰ Similarly, Sextus Empiricus recorded the view that ‘the Cyrenaics also seem to some people to embrace only the ethical part <of philosophy>, and to put aside the physical and logical parts as contributing nothing to living happily’.Footnote ¹¹

Human affairs, which come under the focus of Socrates and his followers, would be included in the author’s category of τὰ τυχόντα (391a23), which are ‘small and worthless compared to the superiority of the cosmos and the greatest things in it’ (391b1–3). Apart from the poor topographers, geographers, historians and other non-philosophers, then, Socratic philosophers could also be said to ‘think much of a minor investigation’ (391a23–4). So, I am suggesting that the opening chapter of De mundo voices not only explicit criticism of non-philosophical disciplines but also implicit criticism of non-metaphysical visions of philosophy.Footnote ¹²

One could object that my suggestion is a mere construal, not something the author himself meant to achieve with his text. I agree that it is difficult to draw the line between actual and apparent criticism, that is, between passages that were in fact written with critical intention and passages into which we project the author’s critical intention. However, in the next section I will review four further cases of explicit criticism, of which at least two (ii and v) are beyond reasonable doubt directed against notable views of rival schools. This indicates that the author of De mundo was aware of views he deemed false and that he was willing to express his disagreement with them.

Now, if he was ready to express his disagreement with rival views explicitly, it is very likely that he was also prepared to do so in a more subtle way, that is, implicitly. And there is no doubt that the author was sufficiently knowledgeable and rhetorically skilful to conceive and deliver such criticisms. So, even if some instances of criticism adduced in this article are questioned or dismissed after closer scrutiny, cumulative evidence of the author’s critical engagement with rival schools remains quite strong.

2.

It is indisputable that we find a piece of intended and fully explicit criticism in the following lines ([Mund.] 2.392a5–9):

This is no doubt intended as setting aright the claim that the word αἰθήρ derives from the verb αἴθεσθαι (‘to burn’). The wrong claim is corrected: the word αἰθήρ actually derives from ἀεὶ θεῖν (‘to run always’).Footnote ¹³ In making the wrong claim, our author goes on to explain, its advocates make a fundamental mistake as to the nature of αἰθήρ, assuming that it is something that burns, which implies that it is of a fiery nature. However, αἰθήρ is of a very special, divine nature that allows it to engage in eternal circular motion, which is disclosed by the correct claim as to the etymology of the word.

Who were the advocates of the wrong claim, that is, the target of the author’s criticism? Reale and Bos think that the target is Anaxagoras, based on Aristotle’s remark in Cael. 3.3.302b4–5 that Anaxagoras called ‘the same substance fire and ether’, repeated in Mete. 1.3.339b21–3.Footnote ¹⁴ True, in Cael. 1.3.270b24–5, right after stating his preferred etymology of αἰθήρ, Aristotle criticizes Anaxagoras for using the word incorrectly when he ‘uses αἰθήρ instead of fire’, but the author of De mundo seems to redirect this criticism against a more likely target, the Stoics. First, the element of fire is given primacy in Stoic physics as the generative principle, origin and end of the cosmos.Footnote ¹⁵ Second, the Stoics spoke of ethereal fire, or ether, in connection with the heavens and celestial bodies.Footnote ¹⁶ Third, they argued that ether is fire with special properties: it is enduring, pure, supremely mobile and rotating.Footnote ¹⁷ Fourth, the Stoics loved to engage in this sort of etymologizing.Footnote ¹⁸ Finally, there is a passage from Philo of Alexandria which derives αἰθήρ from the verb αἴθεσθαι (De confusione linguarum 156.4–157.1):

Von Arnim treated this passage as a testimony of the old Stoics (SVF 2.664), although the Stoics are neither mentioned nor obviously implied in the context of Philo’s passage. However, it is not implausible that Philo’s formulation goes back to the Stoics, given what they say about αἰθήρ elsewhere in other available sources.Footnote ¹⁹

So far, I have reviewed two pieces of explicit criticism in De mundo: (i) one from Chapter 1, directed against non-philosophical disciplines, and (ii) the other from Chapter 2, directed against the Stoic conception and etymology of αἰθήρ. The third piece of explicit criticism is found in the meteorological Chapter 4.

(iii) At the beginning of Chapter 4, the author introduces the Peripatetic theory of two exhalations. First, he gives an overview of the wet exhalation, and then he turns to the dry exhalation. ‘From the dry exhalation,’ he writes in 394b7–9, ‘when it is pushed by the cold so that it flows, wind (ἄνεμος) is created: for this is nothing but a lot of air moving together.’ Then he adds a terminological remark: ‘It is at the same time also called pneuma’, which provides him with the occasion to say the following (4.394b9–12):

Reale and Bos relish this remark because they read it as a reference to Aristotle’s notion of the connate pneuma (σύμφυτον πνεῦμα), which Bos believes is the ‘vehicle of the soul’ and the unrecognized linchpin of Aristotle’s entire philosophy.Footnote ²⁰ The idea of an ‘animating and productive substance in plants and animals’ may well be an echo of Aristotle’s notion of the connate pneuma, even if its description as ἔμψυχoς and γόνιμος is not found in Aristotle’s works.Footnote ²¹ However, Reale and Bos downplay the part in which pneuma is also said to ‘pervade all things’ (διὰ πάντων διήκουσα), which is certainly not Aristotelian but Stoic: the reference seems to be to the theory of the all-pervading pneuma which Chrysippus worked out in detail and which became the Stoic trademark.Footnote ²²

So, the author distinguishes between the ordinary sense of the word pneuma, which he embraces, and the technical sense of ‘the animating and productive substance which is found in plants and animals and which pervades all things’, which he dismisses. This may look like a simple disambiguation, but it is strange that such an important principle would not merit even a short discussion in a treatise on the cosmos. By bringing it up only to dismiss it, after introducing the term ‘pneuma’ in a deflationary way as a generic term for all air currents, the author seems to suggest that the foundational concept in Stoic philosophy called ‘pneuma’ is inconsequential or irrelevant. It is possible, then, that this sidenote was intended as a subtle piece of criticism, and I classify it as explicit criticism because the author expressly states both the preferred and the irrelevant way of using the term ‘pneuma’. It would have been implicit criticism if the wrong or irrelevant view was only intimated or somehow hinted at, rather than spelt out, as it is in our passage.Footnote ²³

(iv) The fourth instance of explicit criticism occurs at the beginning of Chapter 5 ([Mund.] 5.396a33–b7):

Here we find a statement that someone (τις) wondered (ἐθαύμασε), apparently at a definite point in the past, how come the cosmos had not fallen apart long ago, given that it is made of principles with opposite tendencies. This person’s wonder is likened to a hypothetical group of people who would wonder about the persistence of a city-state, given that it is populated by people of different classes, with opposite tendencies. The hypothetical wonder would be premised on the ignorance of civic concord (πολιτικὴ ὁμόνοια), which is a remarkable feature of some well-ordered cities that enables them to enjoy a long and prosperous existence.

Admittedly, the passage contains a piece of explicit criticism of something that stands in need of correction. What needs correction is the defective mental state of ignorance of civic concord, the principle which allows city-states to last as harmonious communities for a long time. Τhe ignorance of civic concord here functions as a proxy for another defective mental state, ignorance of cosmic balance, the principle which allows elementary opposites to work together and build a lasting harmonious whole. As the author goes on to explain, ‘the cause of this [sc. cosmic balance] is the agreement of the elements (ἡ τῶν στοιχείων ὁμολογία), and the cause of the agreement is that they all have an equal share (ἰσομοιρία) and that none of them is more powerful than the other’ (396b34–397a1).

The above-quoted passage contains explicit criticism, because it states both the wrong attitude and the correct one: the wrong attitude is ignorance of civic concord, which causes one to wonder how come cities with diverse populations can last, whereas the correct attitude is appreciation of civic concord, which helps one understand the source of the long existence and prosperity of such cities.

Who is the target of the criticism here? The opening ‘someone’ (τις) may stand for an abstract representative of a certain view or it can function as a literary device to get the author started with Chapter 5, which marks a turning point from which real ‘philosophizing’ and ‘theologizing’ begins in De mundo. However, the target might well be a concrete person, such as Epicurus, who taught that our world, one among countless others, came to be and would fall apart. We have some evidence that the Epicureans mounted different arguments for the perishability of the world,Footnote ²⁴ but no evidence of an argument that the world would collapse specifically because it is constituted of opposites, or of components that have opposite tendencies. The Stoics also argued that the cosmos undergoes periodic destruction and regeneration, and none of their arguments, as far as we know, appealed to the opposites.Footnote ²⁵

There are some reasons to think, however, that the target of the explicit criticism in the quoted passage is specifically Epicurus and his followers. One reason is their attitude to human society. The Epicureans were notoriously suspicious of public life and its vicissitudes. It should suffice to recall Epicurus’ sentence that wise men should ‘free themselves from the prison of general education and politics’ or that ‘a smart person will not engage in public affairs’.Footnote ²⁶ Epicurus espoused private life, with λάθε βιώσας as his famous credo, and his followers pursued that injunction by living in closed communes.Footnote ²⁷ So the Epicureans might be the people who either cannot see or do not believe in the ideal of civic concord, and hence cannot comprehend how city-states can last as long as they actually do, despite being composed of people with opposite interests and tendencies.

The other reason for thinking that the target of criticism is Epicurus can be found in a reference to the notion of ἰσονομία. As Cicero writes, ‘in the sum of things everything has its exact match and counterpart. This property is termed by Epicurus as ἰσονομία, or the principle of uniform distribution.’Footnote ²⁸ This is a general principle that each thing has its exact counterpart. What follows from this principle, in Cicero’s words, is that, ‘because there are forces of destruction, there are also forces of preservation’.Footnote ²⁹ Although the author of De mundo does not use the exact term ἰσονομία, he does use the similar word ἰσομοιρία, apparently with a large overlap in meaning. The idea that the elements have an equal share in the universe, so that none overpowers the others, seems equivalent to the idea that each element has its counterpart in another element, so that the opposite tendencies of the elements are kept in balance. If that is correct, what we find in the quoted passage from Chapter 5 of De mundo is criticism of Epicurus by appealing to his own principle: the principle of ἰσονομία, or some equivalent thereof, explains the agreement and cooperation of the elements that make the cosmos everlasting. In other words, had Epicurus fully grasped his own principle, he would not have ‘wondered how the cosmos, consisting of opposite principles, I mean dry and wet ones, cold and warm ones, has not long ago been destroyed and perished’ (396a33–b1).

(v) The fifth and final instance of explicit criticism is widely recognized among scholars. It is found at the beginning of Chapter 6, where the author takes issue with the idea that God operates in the cosmos by being present himself in the cosmos and meddling with individual things in it. ‘God really is the preserver of all things and the begetter of everything’, the author writes at 397b20–3, ‘no matter how it is brought about in the cosmos, but not by himself enduring the hardship of a creature hard at work (οὐ μὴν αὐτουργοῦ καὶ ἐπιπόνου ζῴου κάματον ὑπομένων)’. He continues (5.398a1–11):

Many scholars have observed that the author of De mundo is here attacking the Stoic idea of God who governs the cosmos in the guise of divine pneuma that permeates all and mixes with every bit of ordinary matter, large and small.Footnote ³⁰ Pohlenz goes as far as to say that this passage is a ‘declaration of war’ on the Stoic doctrine of God’s immanence.Footnote ³¹ The author of De mundo singles out two inappropriate and demeaning consequences of this doctrine: (i) God is subject to toil and hard labour, and (ii) God is present in foul and undignified things. The first consequence would be something that the Aristotelians as well as the Epicureans would be keen to raise as an objection against the Stoics, stressing the divine attribute of aponia. The second consequence has in fact been quoted many times by the Stoics’ opponents of all colours.Footnote ³²

So, this passage is clearly an instance of explicit criticism, since the author states both the view that stands in need of correction and the correct view, although he does not name the advocates of the wrong view. However, the verbs διήκειν and φοιτᾶν, which are commonly used by the Stoics to describe the pervasive activity of the divine principle, in conjunction with the widespread objection raised against the Stoic view of divine immanence, are sufficiently clear indications of the intended target of the author’s criticism.

3.

So far, I have reviewed five cases of explicit criticism; now I turn to implicit criticism. Like every other sort of criticism, implicit criticism is a statement that is intended to set something aright, be it a claim, a view, an attitude, a work of art, a person or whatever (from this point on, I will write about claims, for the sake of simplicity). So, criticism aims at correcting a wrong claim. This correcting is typically achieved by stating the wrong claim and then replacing it with the right claim, or vice-versa: ‘It is not p, but q’ or ‘It is q, rather than p’. This is the basic scheme of what I call ‘explicit criticism’, and I have argued that we find five instances of such criticism in De mundo.

The corrective function can, however, also be achieved in a more subtle way, by stating only the right claim, provided that it is sufficiently clear from the context, or otherwise indicated, what the wrong claim is, so that the reader can decipher what is being corrected and how.Footnote ³³ One efficient way to allude to the wrong claim without expressing it is to use terms or motifs recognizably associated with the wrong claim or its prominent advocates. For example, in Menexenus, Plato attacks Thucydides’ famous funeral oration by having Socrates attribute his funeral oration to Aspasia and by incorporating verbal echoes of Thucydides.Footnote ³⁴ In Physics 1.8, Aristotle evokes the Eleatic doctrine of being, which he submits to criticism, by playing on the metaphor of path (ὁδός) that dominates Parmenides’ poem On Nature.Footnote ³⁵ In his Meditations 6.10, Marcus Aurelius introduces the Epicurean vision of the cosmos, which he opposes, by exploiting Epicurean technical terms such as περιπλοκή and σύγκρισις.Footnote ³⁶ The author of De mundo employs the same device in the five passages to be reviewed in the present section.

(i) Let us start with a remarkable passage ([Mund.] 5.396b28–34):

This passage is remarkable for several reasons. First, the thing that ‘pervades all things’ is a power, not a material substance, as in Stoic theory. Here the author uses the Stoic terminology of διὰ πάντων διήκειν to evoke the notion of a divine material substance that pervades all things and, depending on its τόνος, gives them coherence, growth, perception, self-motion and reason. However, what is said to pervade all things is not a material substance but something immaterial, namely a power that emanates from God, as will be established in Chapter 6 of De mundo. So, I take it that this is a piece of implicit criticism of the Stoics, since only the right claim is expressed, and it is formulated in terms that immediately evoke the wrong claim. The implied wrong claim is, of course, that there is a material substance that pervades all things, that is, the Stoic pneuma,Footnote ³⁷ and the stated right claim is that there is an immaterial power that pervades all things.

Second, the passage is remarkable because it speaks of the cosmos as having been ‘fashioned’ (δημιουργήσασα, 396b31). Third, this and the other verbs in the passage are in the aorist (διεκόσμησε, ἀναγκάσασα, μηχανησαμένη, 396b28–33), suggesting that the cosmos had a beginning at some point in the past, or rather at the same point at which time itself was created. A hint at Plato’s account of the creation of the cosmos in the Timaeus is unmistakeably detected in the verb δημιουργεῖν and further bolstered by the verbs in the aorist. However, the idea that the world was created by a demiurge is soon superseded by an affirmation of the Peripatetic doctrine of the eternity of the world towards the end of Chapter 5.Footnote ³⁸ It is as though the author wanted to say: ‘Yes, the cosmos could very well be seen as a product of demiurgic activity, for it really does look as if it was fashioned, but this is a wrong supposition, since the cosmos has always been and always will be as it is now.’

What I am proposing, then, is that the quoted passage contains two distinct pieces of implicit criticism, one of the Stoic doctrine of pneuma and the other of Plato’s account of creation in the Timaeus.Footnote ³⁹

(ii) The latter part of Chapter 5 contains a passage that is sometimes described as laudatio mundi (397a4–17). It opens by calling the cosmos περικαλλέστατος and then proceeds to ask what could be better than it, more beautiful, more orderly, more reliable, closing with a series of superlatives ([Mund.] 5.397a14–17):

Calling the cosmos beautiful and unageing is unmistakeably Platonic.Footnote ⁴⁰ The Platonic trope of the beauty and grandeur of the cosmos, with the whole series of superlatives, is meant to underline that the cosmos is very special and most wonderful, and this might have been directed against the Epicureans, who insist that there is nothing special about this world of ours, or any other world for that matter. A particular stab at the Epicureans might be detected in the claim that the cosmos is ‘unageing’ (ἀγήρως). Epicurus argued, possibly inspired by the earlier atomists, that the cosmos, despite being an inanimate aggregate of atoms, between its generation and its dissolution goes through a process akin to the growth, maturity and decline of living beings.Footnote ⁴¹ This process depends on the exchange of matter with the environment, similar to nutrition in living beings, where levels of absorption inevitably decline over time.Footnote ⁴² Given that our author, in contrast to Plato and the Stoics, does not think that the cosmos is a living being, his statement that the cosmos is ‘unageing’ cannot be taken at face value. It is reasonable to suppose that he is deliberately evoking Plato here to assert the grandeur of the cosmos, but the choice of ἀγήρως—uncoupled from ἄνοσος—at this juncture might have been intended to bring the Epicureans to mind. If so, this would count as an instance of implicit criticism, since only the right view is stated (‘the cosmos is beautiful and special’), whereas the wrong view (‘this cosmos is neither particularly beautiful nor more special than any other’), championed by the Epicureans, is left unexpressed and is merely hinted at.

Adding at the end of our passage that the cosmos is imperishable (ἄφθαρτος) goes beyond what Plato explicitly said, although this is very probably what he believed.Footnote ⁴³ What is uncontroversial, on the other hand, is that the Epicureans and the Stoics took the view that the cosmos is perishable, though they understood this differently.Footnote ⁴⁴ According to the Epicureans, the cosmos is perishable in the sense that every cosmos, being an aggregate of atoms, undergoes the natural process of growth and decline before falling apart. According to the Stoics, by contrast, the cosmos is perishable in the sense that this one and only, most rational and the best possible world undergoes periodic conflagration, after which it restarts and unfolds in exactly the same way.Footnote ⁴⁵ In any case, given that the perishability of the cosmos was a hallmark of these two philosophical schools, stating only the author’s preferred, Aristotelian view that the cosmos is imperishable can be read as a piece of implicit criticism.

There is more to this passage. The attributes of being supremely beautiful and powerful as well as free from ageing and destruction are traditionally reserved for divine beings, and yet our author—quite tellingly—stops short of claiming that the cosmos is divine. In stark contrast to Plato and the Stoics,Footnote ⁴⁶ the author of De mundo reserves this qualification only for God, in Chapter 6 (and, derivatively, for philosophy, which enables us to attain a comprehension of God).Footnote ⁴⁷ So, the whole laudatio mundi passage, ending with the claim that the cosmos is imperishable, can be read as an implicit criticism of all three major rival schools of philosophy, Epicureanism, Stoicism and Platonism. More precisely, stressing the grandeur of the cosmos with the help of Platonic vocabulary is directed against the Epicureans, whereas omitting to say that the cosmos is a living being or something divine is directed against both the Stoics and the Platonists.Footnote ⁴⁸

(iii) At the beginning of Chapter 2 the author describes the centre of the cosmos ([Mund.] 2.391b12–14):

The first thing to note here is the periphrastic description of the Earth as ‘unmoved and fixed’ (ἀκίνητόν τε καὶ ἑδραῖον). These two adjectives are not synonymous: ἀκίνητος denotes, primarily, the lack of local motion or even the inability to engage in local motion, whereas ἑδραῖος denotes stability, fixedness, firmness. In other words, the first adjective says that the Earth does not go from one place to another, while the second ensures that it does not engage in any other sort of local motion. The author may want to ensure this, because there is a distinguished line of interpreters of Plato’s Timaeus, including Aristotle and Plutarch, to the effect that the Earth is stationary in the middle of the cosmos but rotates around its axis.Footnote ⁴⁹ Indeed, this is the position advocated by Plato’s pupil Heracleides of Pontus and by Pythagoreans such as Hicetas and Ecphantus.Footnote ⁵⁰ So, if one wanted to attack the claim that the Earth is fixed in one place but rotates around its axis, the adjective ἀκίνητος would not be sufficient; one would need to add an adjective like ἑδραῖος.Footnote ⁵¹ Thus I take the description of the Earth as ἑδραῖος to be an instance of implicit criticism of the Platonists and the Pythagoreans who maintained that the Earth, though fixed in the centre of the cosmos, rotates around its axis.

But there is more to this passage. Calling the Earth ‘life-bearing’ (φερέσβιος) goes back to the Homeric Hymns and to Hesiod. Likewise, calling it ‘Hestia’ is commonplace among the Presocratics.Footnote ⁵² However, calling the Earth ‘Hestia’, right after saying that it is located in the very centre of the cosmos, might be a stab at the Pythagorean theory of the central fire. Philolaus is known to have argued that there is a fire in the centre of the cosmos and he expressly called this fire ‘Hestia’.Footnote ⁵³ So, this passage might also contain implicit criticism of the Pythagorean theory of the central fire.

(iv) Another passage that can be read as a piece of implicit criticism occurs later in Chapter 2, where the author summarizes his description of ether ([Mund.] 2.392a31–4):

Ether is not only ‘well ordered’ but also ‘unchangeable, unalterable and unaffected’. This series of adjectives is supposed to ensure that ether is free of all change or affection. This can be mere rhetoric, of course, but one adjective sticks out: ἀνετεροίωτος. This rare privative adjective seems to signify the inability to undergo ἑτεροίωσις, that is, alteration or differentiation of some sort. Opting for this adjective over the more common ἀναλλοίωτος might be the result of the author’s rhetorical exuberance, but it might also have something to do with the fact that the word ἑτεροίωσις had a special place in Stoic philosophy.

Sextus Empiricus documents the Stoic controversy concerning the definition of appearance (phantasia).Footnote ⁵⁴ The founder of the Stoic school, Zeno of Citium, defined it as an ‘impression of the soul’ (τύπωσις ψυχῆς). Zeno’s successor, Cleanthes of Soli, interpreted this literally, adducing the example of an impression that a signet ring leaves in wax. Chrysippus objected that we can have conflicting appearances at the same time, whereas nothing can be imprinted in conflicting ways at the same time, so he proposed to define appearance as an ‘alteration of the soul’ (ἑτεροίωσις ψυχῆς) and supported it with the following example: ‘For just as air, when many people are speaking, receives an untold number of different impacts at once, and right away the alterations (ἑτεροιώσεις) that it takes on are also many, so too the leading part, when it has a variety of appearances, will experience something analogous to this.’Footnote ⁵⁵ According to Chrysippus, then, ἑτεροίωσις is a sort of subtle alteration that fine substances such as air and pneuma can undergo, which allows them to acquire a multitude of properties at the same time. Sextus glossed this kind of alteration as ‘outlandish’ or ‘magical’ (τερατολογουμένη ἑτεροιωτική [sc. τύπωσις]).Footnote ⁵⁶

If the substantive ἑτεροίωσις and its compounds were indeed recognizably Stoic, the rare privative adjective ἀνετεροίωτος might have been deliberately chosen by the author to invoke the Stoics in the mind of his audience, since the Stoics taught that ether, although pure and divine, is somehow alterable between air and fire.Footnote ⁵⁷ By contrast, our author maintains that ether is isolated from the four elements and absolutely unalterable, and for that purpose he uses the rare adjective ἀνετεροίωτος. Whether or not the adjective was meant to pick up a conspicuously Stoic term, in this passage the author of De mundo seems to be hinting at the Stoic position that he considers in need of correcting, thus delivering a piece of implicit criticism.

(v) Chapter 6 of De mundo explains the relation of God to the cosmos. The main idea is that God does not need to be present in the world to be causally efficient in it; rather, he is efficient through his ‘unrelenting power’ which spreads from the periphery of the cosmos down to every corner in the centre. To drive this idea home, the author introduces a long series of interlocking analogies, such that every succeeding analogy fixes a gap or problem in the preceding one.Footnote ⁵⁸ The first and most elaborate analogy is with the Great King of Persia, who rules an enormous empire through a hierarchical network of officers, without himself ever leaving the palace and remaining ever invisible to his subjects, which is considered a mark of his dignity. If it is dignified for a human to rule without ever leaving his court, how much more dignified must it be for God to operate in the cosmos without ever descending from ‘the highest and first place’ (τὴν ἀνωτάτω καὶ πρώτην ἕδραν, 397b25)?

However, the analogy between the Great King and God breaks down at one crucial point: God has ‘no need of the contrivance and support of others’, whereas ‘rulers among us human beings need the help of many hands (πολυχειρίας <δεῖ>) because of their weakness’.Footnote ⁵⁹ Not needing the assistance of others to produce the desired effects, that is, the ability to ‘produce all kinds of effects with ease and simple movement’, is ‘the most divine thing of all’ (τὸ θειότατον, 398b13). To illustrate this point, the author introduces the next two analogies, with engineers and puppeteers who produce a series of different effects in their contraptions by the simple actions of releasing a spring or pulling a string.

The author’s statement that requiring the help of many hands is a mark of weakness might be an implicit criticism of Plato’s account of creation in the Timaeus, in which the divine demiurge is unable to create three mortal kinds of living beings (plants, animals and humans), so he needs the assistance of the lesser gods. ‘If these creatures came to be and came to share in life by my hand,’ Plato’s demiurge says to the lesser gods, ‘they would rival the gods. It is you, then, who must turn yourselves to the task of fashioning these living beings, as your nature allows.’Footnote ⁶⁰

4.

In the previous two sections, I discussed five instances of explicit and five of implicit criticism in De mundo.Footnote ⁶¹ The most common target, of both explicit and implicit criticism, seems to be the Stoics. They are attacked for their views on God’s immanence, pneuma, ether, the perishability of the cosmos, and perhaps also for their view that the cosmos is alive and divine. It is not difficult to envisage why the author should be particularly keen to criticize the Stoics. They were the leading and most influential school of the Hellenistic period. What is more, they had a comprehensive and coherent philosophical system with a grand cosmological vision. However, the author of De mundo seems to have disliked their vision rather strongly, probably because he found Stoic materialism, especially the theory of all-pervading pneuma and God’s immanence in the world, philosophically unsound and theologically repugnant.

The next target is the Epicureans, another prominent school in the Hellenistic era. They are criticized for their lack of metaphysical vision, misconception of the cosmos, failure to draw consequences from the principle of ἰσονομία, and perhaps also for their disbelief in political ideals such as civic concord. Plato is criticized for his view that the cosmos was created, possibly also for his ideas that the demiurge needed the assistance of the lesser gods and that the Earth in the centre of the cosmos rotates around its axis. All of these ideas are found in a single work of Plato, the Timaeus, interpreted literally.

However, the author must have been familiar with Plato’s other works, since he concludes the treatise (7.401b24–9) with a quote from Laws.Footnote ⁶² Moreover, he alludes in the opening chapters to Phaedrus and Republic respectively with ‘the intellect as the guide of the soul’ and ‘the divine eye of the soul’ (1.391a11–12 and 15), and to Apology, Crito and Phaedo with the striking examples of different effects of the law in a city: ‘one person walks to the courts to defend himself, still another to prison to die’ (6.400b19–20). Our author clearly holds Plato in high regard, since he borrows liberally from Plato in Chapter 1 and in the laudatio mundi passage in Chapter 5, and in Chapter 7 he speaks of ‘the noble Plato’. Surely, our author had strong sympathies for Plato’s metaphysical vision of philosophy and appreciation of the cosmos, but he also had objections to Plato’s conception of the cosmos, notably to the view that the cosmos was created, and possibly also to the view that it is alive and divine. In addition, as noted above, the author might have had reservations about Plato’s conception of a God who needs assistance from the lesser gods to complete his work. If the author attributed to Plato the view that the Earth rotates around its axis in the centre of the cosmos, as Aristotle himself did, this might have been the object of his criticism, too. If not Plato, some Pythagoreans might have been implicitly criticized for advocating this view, others for thinking that the centre of the cosmos is occupied by fire, not by the Earth. Finally, it is possible that the Cynics and the Cyrenaics were also implicitly criticized in the opening chapter for their lack of metaphysical vision.

A general pattern can be discerned in the author’s lines of criticism. De mundo starts with criticism of non-philosophical disciplines in order to assert the pre-eminence of philosophy, and then continues with criticism of other philosophies in order to assert the Peripatetic philosophy against its rivals. More to the point, non-metaphysical and anti-intellectualist philosophies are criticized more harshly than metaphysical philosophies. Stoic philosophy is criticized most frequently and in both ways, explicitly and implicitly. By contrast, Plato, whose metaphysical philosophy and appreciation of the cosmos are dear to the author, is criticized only implicitly, for his views about the cosmos and God.

If the main thesis of this article is accepted and it is granted that at least some of the surveyed passages were written with the intention of criticizing views of rival philosophical schools, this would mean that De mundo must have been written after Epicurus (341–270) and, in particular, after Chrysippus (279–206), ‘the second founder of Stoicism’, who is responsible for much of the success of Stoicism as one of the most influential philosophical movements for centuries in the Greek and Roman worlds.

It is possible that De mundo was a Peripatetic response to the rising popularity of Stoicism owing to the spread of Chrysippus’ works, at the end of the third and the first half of the second century b.c.e., when Epicurean philosophy was very much alive, and representatives of the Socratic schools were still around.Footnote ⁶³ However, this was the period of the sceptical ‘New’ Academy, which focussed on Plato’s Socratic dialogues and showed little interest in the Timaeus, as far as we know. If I am correct that our author reacted to this dialogue of Plato, it is tempting to date De mundo in the first century b.c.e., which saw renewed interest in the Timaeus, not only inside the Academy, which took a dogmatic turn with Antiochus of Ascalon (c.125–c.68), but also among philosophers associated with other philosophical schools.Footnote ⁶⁴ For example, we know that the leading Stoic of the time, Posidonius of Apamea (c.135–c.51), had a keen interest in Plato’s Timaeus and that he might have written a commentary in which he focussed on the Pythagorean elements in that dialogue.Footnote ⁶⁵ On the other hand, the Peripatetic philosopher Xenarchus of Seleucia (fl. 60 b.c.e.) studied and presumably also wrote on the Timaeus.Footnote ⁶⁶

A further advantage of placing De mundo in the mid first century b.c.e. is that Posidonius could then be the source of the first definition of the cosmos, which we find at the beginning of Chapter 2 of De mundo, and of many meteorological terms and explanations in Chapter 4.Footnote ⁶⁷ Moreover, a recent study of archaeological evidence about the Achaean cities of Helice and Boura, allegedly destroyed by an earthquake and tsunami ([Mund.] 4.396a17–21), also supports this (or not much later) dating.Footnote ⁶⁸

Quite generally, the first century b.c.e. was a period of especially intense interactions among different schools of philosophy, during which Plato and Aristotle began to be regarded as philosophical authorities.Footnote ⁶⁹ It is likely that the author of De mundo was an active participant in these interactions, writing this treatise with the aim of defending the Peripatetic vision of God and the cosmos against the rival ones on the market. He seems to have thought that the best way to do so was to pass the text as Aristotle’s own,Footnote ⁷⁰ which required him either to abstain from critical engagement with post-Aristotelian schools or to do so subtly and without naming. He opted for the latter, as this article has argued.

De mundo is not an eclectic compendium of largely Peripatetic doctrines garnished with rhetorical fireworks, as it might seem at first glance. On the contrary, it is a sophisticated text alert to rival visions of philosophy and conceptions of the cosmos, with which it engages tactfully and in ways appropriate to the task of selling the treatise as Aristotle’s own.