It seems that the Cyrenaics did not have detailed linguistic and semantic views. However, the Sextus passage (T6b) cited in the previous chapter (pp. 89–90) indicates that some Cyrenaic positions are relevant to language. These are the following: (i) the pathē are private; (ii) nobody has access to the pathē of anyone else: in that sense the pathē are incommunicable; (iii) there is no common criterion, which on one interpretation entails that no proposition is evidently true of an object or state of affairs in the world, but on another interpretation (outlined at the end of the previous chapter) entails that we cannot establish truths about shared experiences. On the other hand, (iv) the onomata which we use are koina, commonly shared; also, the text suggests that (v) there is a disparity between the lack of a common criterion and the use of commonly shared onomata. The point appears to be that, when I and my neighbour both use the word ‘white’ in relation to the same thing, we tend to assume that the content of our pathē is qualitatively identical; yet we should not assume this, because of (i), (ii) and (iii).

In what follows, I shall first specify what the expression ‘common names’ (koina onomata) may mean, what entities are ‘the things’ designated by these ‘names’, and what semantic relation is indicated by the statement that common names are ‘assigned’ (tithesthai) to things.

In the two subsequent chapters, I shall turn to the parallels drawn by ancient authors between the Cyrenaic position on the one hand, and the doctrines of Epicurus and of Protagoras in Plato's Theaetetus on the other hand. My aim is to show where the Cyrenaic position approaches certain varieties of empiricism and relativism, and also where it diverges from either of these positions. If this is achieved, we may reach a better understanding of the bounds and limitations of the Cyrenaic doctrine.

I shall start with Plutarch [T1], who raises the issue of the relation between Cyrenaic scepticism and Epicurean empiricism. Plutarch's testimony [T1] consists of two parts. In chapter 6 I discussed the first part of the testimony (1120c–f), in which Colotes comes out as an unreliable and even malicious historian, but as a good philosopher. This picture changes in the second part of Plutarch's passage (1120f–1121e), in which Colotes is accused of philosophical naivety on two accounts. First, Plutarch maintains that Colotes fails to see that he is attacking the very tenets which, as an Epicurean, he is bound to endorse.

The evidence on Cyrenaic epistemology comes from secondary sources and consists entirely of testimonies, not of fragments. None of the titles mentioned in the lists of the doxographers seems to be of an epistemological treatise. But the lists refer only to the works of Aristippus of Cyrene, Theodorus and Hegesias, and none of them is known to have had detailed epistemological views. The epistemology of the school may have been developed in treatises of Aristippus the Younger and Anniceris, probably under the heading of ethics.

Although the testimonies are second-hand and occur principally in polemical contexts, they are often based on good sources and constitute reliable evidence about the Cyrenaic positions. Also, the polemical arguments brought against these positions by ancient authors are frequently enlightening. In my selection of texts, I have included the epistemological testimonies, and also materials on psychology and ethics that have a bearing on the topics that I discuss.

COLOTES AND PLUTARCH

Our earliest source on the Cyrenaic theory of knowledge is Colotes, a young contemporary of Epicurus. After Epicurus' death (271 bc) and Arcesilaus' ascent to the leadership of the Academy (some time in the 260s bc), Colotes wrote a book entitled On the Fact that it is not Possible even to Live according to the Doctrines of the Other Philosophers, in which he criticised the doctrines of Parmenides, Empedocles, Socrates, Melissus, Plato, Stilpo, and two schools which he does not name but which are easily identified as the Cyrenaics and the followers of Arcesilaus.

The Cyrenaics employed two different types of locution to designate pathē. I shall call these types verbal and adverbial.

The verbal expressions consist of present-tense passive verbs. We find them in the testimonies in the first and third persons, singular and plural, and in the infinitive. Colotes attempts to ridicule the Cyrenaics by attributing to them the claim that ‘they are themselves being walled (toichousthai) and horsed (hippousthai) and manned (anthrōpousthai)’ (1120d [T1]); Plutarch denounces Colotes for intentional inaccuracy, and reports what he claims to be the true letter of the doctrine: ‘they say, we are being sweetened (glykainesthai) and bittered (pikrainesthai) and chilled (psychesthai) and warmed (thermainesthai) and illuminated (phōtizesthai) and darkened (skotizesthai)’ (1120e [T1]); the anonymous Theaetetus commentator attests the locution ‘I am being burnt’ (kaiomai: 65.33 [T3]), and Sextus mentions the expressions ‘we are being whitened (leukainometha) and sweetened (glykazometha)’ (M v11.191. [T6b]), ‘he is being reddened’ (erythrainetai: 192), ‘they are being yellowed (ōchrainontai) or reddened (erythrainontai) or doubled (dyazontai)’ (193), and ‘being whitened’ (leukainesthai: 197).

The adverbial formulas are constituted by a present-tense passive verb and an adverb. According to Sextus' testimony in T6b, the Cyrenaics maintained that ‘it is probable that one is disposed whitely (leukantikōs diatethēnai) even by what is not white’ (Sextus, M v11.192 [T6b]). They also assumed that ‘the person who suffers from vertigo or jaundice is moved yellowly’ (ōchrantikōs kineitai: ibid.).

PHYSIOLOGY

Pleasure and pain are pathē (singular, pathos). The term pathos is related to the Greek verb paschein (‘to undergo’, ‘to suffer a change’), and denotes effects upon a subject, usually caused by contact with an external object. Depending on the context, a pathos may occur in inanimate substances or in animate beings, and may be an entity or an occurrence of various kinds: a stone heated by the sun undergoes a pathos and becomes warm; the diagnosis of a disease is sometimes effected by observing the pathē or physical symptoms displayed by the patient; and the pain that the patient feels is a pathos as well.

Although the Cyrenaics focused on pathē in connection with perceivers, their analysis preserves physicalistic overtones. These are reflected, I believe, in the definitions of pleasure and pain as smooth and rough motions located in the flesh (Sextus, PH 1.215 [T6a]) or in the soul (D.L. 11.90 [T7c]), which are somehow related to pleasurable and painful feelings. There is little direct evidence about the nature of these motions, but, in my view, ‘smooth’ and ‘rough’ designate empirical properties of physical changes in the body and do not refer to the way these changes feel to the perceiver. First, pleasure does not feel smooth but pleasurable, and pain does not feel rough but painful.

The restricted scope of the Cyrenaic criterion constitutes the target of the Peripatetic philosopher Aristocles of Messene, whose criticism of the Cyrenaic theory is reported by Eusebius.

At the outset, Aristocles sketches out the theory which he intends to attack in the following terms.

Aristocles' objections are not targeted against the affirmation that the pathē are apprehensible, but against the restrictive claim that only they can be apprehended. His goal is to show that the Cyrenaic position is inconsistent by arguing that we know many things in addition to our pathē, or that our awareness of pathē entails (or presupposes) that we know things about external objects.

Having answered the most serious criticisms of his account, Aristotle concludes his arguments that the earth must be a sphere – and so concludes De Caelo II - with the particulars of its size. De Caelo III, 1, opens with a brief summary of what has been discussed thus far concerning the first heaven and its parts, the stars carried in the heaven, and the composition and nature of these things, including, finally, that they are ungenerated and incorruptible (298a24–27). Having dealt with the first (and highest) element, aether, Aristotle turns to the other elements.

These elements – each of which possesses its own specific nature – are “by nature.” Natural things are either substances or operations and affections of substance. “Substances” refers to the elements – aether, air, fire, water, and earth – and things composed of them, such as the heaven, as a whole and its parts, as well as plants and animals and their parts; “operations and affections” include movements of each of these according to their proper power as well as their alterations and transformations into one another. Obviously, Aristotle concludes, the study of nature is for the most part concerned with bodies because all natural substances are either bodies or come to be after bodies, and all involve magnitude. The investigation must also include generation and destruction, as “operations and affections” of the elements and all things composed of them (298b8–11).

“Nature is everywhere a cause of order.” This claim, together with the evidence that Aristotle marshals to support it, forms a consistent theme throughout his entire corpus. There has been and continues to be considerable disagreement about Aristotle's various arguments – their topics, what they say, if they are valid. But there can be neither doubt nor quarrel that within his philosophy as a whole this claim is central: nature is everywhere a cause of order.

As Mansion argues, nature gives the world not only order, but intelligibility. I shall conclude that Aristotle's claim that nature is everywhere a cause of order constitutes a first principle that informs his physics as a science, and consequently, the particular problems and solutions within physics. Beyond his physics, it also appears at work within his metaphysics. Indeed, it constitutes one of his most important philosophic commitments.

As a first principle, this claim is never proven and so is not derived by or within physics – or any other science. Rather, as I shall argue, the topics, proofs, and arguments of Aristotle's physics and metaphysics presuppose and work in terms of the claim that nature is everywhere a cause of order. Hence, we see this claim at work because we see the physics that assumes it as a first principle.

When, at the opening of Physics III, 1, Aristotle lists those things without which motion seems to be impossible, the infinite appears first, followed by place, void, and time. He examines the infinite after completing his account of motion (Physics III, 4–8). I omit examination of it here for two reasons. (1) As noted earlier, the infinite, place, void, and time are subordinated to the definitions of motion and nature, but they are not subordinated to one another. Thus it is not necessary to examine the infinite in order to examine place and void. (2) Furthermore, the infinite plays a largely negative role in the order of nature. There is no such thing as an infinite magnitude, and indeed the being of the infinite is matter and even privation (Physics III, 7, 207a35, 208a). However, when Aristotle identifies the infinite with matter and privation, he anticipates his account of place in an important way.

As matter or privation, the infinite is identified with what is surrounded rather than with what surrounds, which is form (207a35–36; 208a3–4). Place, as we shall see, is not itself form, but strongly resembles form: both are limits (Physics IV, 4, 211b13). Ultimately, Aristotle defines place as the first unmoved limit of that which surrounds (212a20–21). As I shall argue, place, as a first limit, serves as a cause of order: it renders the cosmos determinate in respect to “where things are and are moved.”

With the account of the nature and activities of the elements, the analysis of place and the elements is complete. Taken together “the where,” i.e., place and not void, and inclination, i.e., the active orientation of each element toward its respective proper place, exhibit the order of nature in Aristotle's physics. Nature is always a cause of order, and that order is constituted within the world by two principles. Place is the first limit of the containing body and renders the cosmos orderly in respect to direction; thus the cosmos exhibits “up,” “down,” “left,” “right,” “front,” and “back” immediately and intrinsically in itself. Second, inclination constitutes the very nature of each element as an intrinsic source of being moved toward its proper place, e.g., up for fire and down for earth; consequently, elemental motion is never random or irregular because, in the absence of hindrance, each element cannot fail to be moved toward (and to rest in) its proper place.

These principles solve a number of problems and so express the order of nature in three ways. (1) Place renders the cosmos determinate in respect to “where,” while each element is ordered to its proper place. Place and the inclination of each element work together to produce the order of nature in respect to the intrinsically directional motion of the elements.

The conclusion that the elements are generated from one another raises the question of how this generation occurs. This question – indeed, the issue of the generation of the elements generally – presupposes a prior problem: what differentiates the elements? This problem is serious for two reasons. First, whatever differentiates each element must be generated when the element is generated. Second, whatever generates each element renders it unique and so makes the element be what it is according to its definition. Hence an account of what differentiates each element is central to the nexus of topics concerning the generation of the elements, their natures and motions. This “prior problem” is solved in the remainder of De Caelo III and IV, and the final account of the generation of the elements appears in the De Generatione et Corruptione.

Aristotle first criticizes his predecessors (De Caelo III, 7 and 8). The followers of Empedocles and Democritus explain the generation of the elements as an excretion of what is already there; this view reduces generation to an illusion – as if it requires a vessel rather than matter (De Caelo III, 7, 305b–5). And Aristotle quickly shows that it entails that an infinite body is contained in a finite body – which is impossible (305b20–25).

On other accounts, the elements change into one another, by means of shape or by resolution into planes (305b26).