In ‘The Stoics on Conceptions and Concepts’, Katerina Ierodiakonou offers an account of the Stoics’ distinction between ennoiai and ennoēmata (‘conceptions’ and ‘concepts’), and also of the distinctions suggested by the standard Stoic terminology of concepts also mentioned above: notably, prolēpseis (‘preconceptions’), phusikai ennoiai (‘natural conceptions’), and koinai ennoiai (‘common conceptions’). All these terms appear intended to point to general notions that play a central role in the acquisition of human knowledge, but it remains puzzling how exactly the Stoics understood them or why they introduced them into their doctrine in the first place. Ierodiakonou addresses these issues, as well as further questions debated in the secondary literature. These include whether all human beings necessarily possess concepts or just have the ability to possess them, what is the content of conceptions and how it is determined, what is the ontological status of conceptions and concepts, and what are their epistemological functions.

The chapter ‘Alexander of Aphrodisias on Concepts’ by Frans A. J. de Haas takes up another aspect of concept theory, that is, the endeavour to define what a concept is. Furthermore, he explores the interactions between the Peripatetics and the Stoics, as they are evidenced by Alexander, on ontological as well as psychological and epistemological issues. De Haas also offers a systematic study of part of Alexander’s rich vocabulary denoting concepts, thoughts, and universals, and of a correspondingly rich collection of verbs referring to the human activities of abstracting or constructing concepts. Importantly, this analysis sheds light on Alexander’s understanding of ennoia and noêma, and on Alexander’s views concerning the epistemic reliability of concepts and the unity of concepts in the human soul.

Matthew Duncombe’s chapter ‘Relative Concepts’ asks: what are relative concepts according to ancient philosophers? Duncombe argues that Plato, Aristotle, and the Stoics have a clear concept of relatives, distinct from incompleteness approaches, which he calls ‘constitutive relativity’. The core idea of constitutive relativity is that a relative is constituted precisely by the relation it bears to an exclusive correlative. Duncombe discusses particular philosophers and schools in detail. The examination of Agathon’s speech in Plato’s Symposium illustrates that Socrates understands relative concepts in general and love in particular, on the constitutive model. Aristotle’s concept of relatives in Categories 7 draws on Plato, but Aristotle addresses a worry that relative concepts might be vacuous. Duncombe argues that a Stoic relative concept is the concept of a relative that relates exclusively to a correlative. He examines Sextus’ sceptical argument, which raises a worry about any conception of relativity where relatives relate exclusively to their correlatives.

Plutarch is well known as a generally even-tempered expositor of the great tapestry of Greek history, literature, and philosophy, and a benign counselor on questions of ethical conduct and social mores, but there is another side to him, that of the accomplished polemicist, primarily in the area of philosophy, but also concerning his predecessors in the craft of history, and on occasion the poets as well. In all of Plutarch’s polemics, we can discern common threads. While historians (especially Herodotus) and poets are criticized primarily for their flawed socioethical views, the Stoics, Epicureans, and even Plutarch’s predecessors in the Platonic tradition have the inconsistencies in their positions relentlessly skewered, and the most absurd consequences of their misguided arguments teased out. This essay surveys a selection of Plutarch’s critiques of previous historians, then casts a brief glance at his censure of the poets, before turning to an examination of his polemics against rival philosophical schools, and lastly rival views within the Platonist tradition.

The Stoics break with Plato and Aristotle, who envisaged the value that makes a life worth living as a degree or part of the value that makes a life happy. Instead, they establish two separate axiological scales, one that determines whether a life is happy, and another one that determines whether it is worth living. The former contains virtue and vice, or what is good and bad, whereas the latter is defined by the so-called preferred and dispreferred indifferents, such as health, wealth or renown. This allows for the possibility that a virtuous and happy person sometimes ought to depart from life, when they do not have a prospect of a life worth living, while a vicious and unhappy person ought to stay alive, when they have such a prospect. This decoupling of the happy life from the worthwhile life is consistent with the Stoic view that life itself is a preferred indifferent, and hence the deliberations about staying alive should be referred to other preferred indifferents rather than to virtue and vice.

The chapter deals with Galen’s attack on the pulse-classification of the first-century CE Pneumatist doctor Archigenes, and examines Galen’s reasons for replacing Archigenes’ theory with his own. Galen claims that Archigenes has no idea of the proper method of determining the real species of pulse, and he castigates him for terminological failings as well. But it turns out on close analysis that Archigenes’ actual classification is very close to Galen’s own; and the terminological cavils seem fairly trivial and pedantic. So what is the real substance of Galen’s attack? The chapter suggests that the point at issue is partly simply a matter of professional rivalry, but partly also a consequence of Galen’s insistence on adhering to the properly philosophical method of conducting divisions.

These two chapters form a conceptual unity. Their aim is, first, to present and, then, to compare the concepts of technê (art, craft, discipline, expertise) used, respectively, by the Stoics and the Epicureans in different philosophical domains – notably, in cosmology, epistemology and ethics. The main issues to be discussed include the definition of a technê; the criteria determining a technê, the importance of rules and method, the role of experience and practice, the structure of every technê in so far as it is directed towards a goal, the necessary and sufficient conditions for the transmissibility of different sorts of technai and the common assumption that the technai are beneficial for life. Moreover, Tsouna argues that the notions of technê occurring in Stoic and Epicurean texts differ, and she explains how they differ. She suggests that one reason for that fact is that these two schools react in different ways to Plato’s rationalism about technê. On the one hand, the Stoics’ creative appropriation of Plato leads them to formulate a principally rationalistic notion of technê, which is manifest, for example, in their cosmological creationism (cf. the notion of technikon pur), the epistemological distinction between first-order technai and the epistêmê of the wise man, and their ethical conception of the art of living. On the other hand, the Epicureans react to the Platonic heritage in a more negative way and appear to modify their views about technê accordingly. Vis-à-vis the Stoics, they exhibit greater flexibility regarding the criteria of ‘technicity’ and attribute more value to common experience than many Stoics do. Their physical theory precludes any idea of divine craftsmanship. As for Epicurean epistemology and ethics, both involve uses of technê consistent with Epicurean empiricism and the ethical view that pleasure or the absence of pain is the supreme good.

These two chapters form a conceptual unity. Their aim is, first, to present and, then, to compare the concepts of technê (art, craft, discipline, expertise) used, respectively, by the Stoics and the Epicureans in different philosophical domains – notably, in cosmology, epistemology and ethics. The main issues to be discussed include the definition of a technê; the criteria determining a technê, the importance of rules and method, the role of experience and practice, the structure of every technê in so far as it is directed towards a goal, the necessary and sufficient conditions for the transmissibility of different sorts of technai and the common assumption that the technai are beneficial for life. Moreover, Tsouna argues that the notions of technê occurring in Stoic and Epicurean texts differ, and she explains how they differ. She suggests that one reason for that fact is that these two schools react in different ways to Plato’s rationalism about technê. On the one hand, the Stoics’ creative appropriation of Plato leads them to formulate a principally rationalistic notion of technê, which is manifest, for example, in their cosmological creationism (cf. the notion of technikon pur), the epistemological distinction between first-order technai and the epistêmê of the wise man, and their ethical conception of the art of living. On the other hand, the Epicureans react to the Platonic heritage in a more negative way and appear to modify their views about technê accordingly. Vis-à-vis the Stoics, they exhibit greater flexibility regarding the criteria of ‘technicity’ and attribute more value to common experience than many Stoics do. Their physical theory precludes any idea of divine craftsmanship. As for Epicurean epistemology and ethics, both involve uses of technê consistent with Epicurean empiricism and the ethical view that pleasure or the absence of pain is the supreme good.

Chapter 6 is the longest and the most elaborate chapter of De mundo. The topic of the chapter is God and his relation to the cosmos. This relation is explained by a sequence of no less than twelve analogies. It is argued that this proliferation of analogies is not an extravagant rhetorical profusion, but an elaborate explanatory device that affords the reader a fuller grasp of God: the sequence is composed in such a way that one analogy corrects or supplements another, thus building a complex conception of God in the mind of the reader. Following a detailed analysis of the analogies and their relations, the conception of God that emerges is discussed. It is argued that this conception is a distinctly Aristotelian one, albeit with some interesting elaborations and additions. The absence of Aristotle’s technical terms in the explanation of God and his relation to the world, it is suggested, is a consequence of the author’s attempt to make the Aristotelian conception of God attractive to non-Aristotelians as well. This contribution ends with a note on the use of quotations in Chapter 6, since nine out of the twelve quotations in De mundo are found in this one chapter.

Chapter 5 of De mundo is markedly different from the preceding chapters examining technical details of astronomy, geography and meteorology. Chapter 5 takes an overall survey, presenting a view of the whole cosmos as a unified, well-ordered, magnificent and eternal whole – a true kosmos. Chapter 5 can be divided into three parts: the first introduces the Heraclitean principle of the harmony of opposites (396a33–b22), the second shows how this principle applies to the cosmos (396b23–397a5), and the third argues that the cosmos, built on this principle, is majestic and indestructible (397a5–b8). The detailed analysis of each part is accompanied with an attempt to position this text against the views of other Hellenistic philosophical schools, of the Epicureans and the Stoics as well as the Platonists. Having set forth the Aristotelian doctrine of the eternity of the cosmos, it was important for the author of De mundo to show that this does not undermine the beauty and teleological order of the world nor does it remove the need for God, thus setting the stage for Chapter 6.

Broadly speaking, there are two contrasting attitudes towards common sense prevalent in ancient Greek philosophy. On the one hand, there is a dismissive attitude: common sense, understood as what people in general routinely think, is regarded as simply misguided and out of touch with the way things really are. On the other hand, there is a tendency to regard human beings as such as having cognitive capacities that can afford them correct insights – if only they will let these capacities operate as they could or should, without being distracted or misled by various factors that throw them off course. Although these two attitudes are in a clear tension with one another, we frequently find them together in the same philosophers. Indeed, it is not too much to say that we find both strands present, to varying degrees, almost throughout the history of Greek philosophy. This chapter pursues these themes chronologically, touching on several Presocratic thinkers, Plato, Aristotle, the Stoics and Epicureans, and the Pyrrhonian sceptic Sextus Empiricus. Of these, Aristotle is the most sympathetic to common sense, and the Presocratics perhaps the most dismissive, with the others somewhere between these extremes.

“Cynics and Stoics” is an investigation into ecological aspects of both schools’ injunction that individuals should practice “self-sufficiency” (autarkeia) and live “according to Nature.” The relationship of autarky to the sustainability of systems on a global scale is considered in light of Cynic and Stoic cosmopolitanism and virtue ethics. The relationship of subsistence to sustainability is illuminated by Cynic practice and grounded in the modern concept of “appropriate technology.” The Stoic doctrine of oikeiōsis (“proprioception”) is presented as an early instance of an “environmental ethics” that still speaks to the manifold relationships that human beings have to one another and that our species has to the rest of the natural world.

Discourse about justice assesses what each person’s share in the accomplishments of humanity should be. This is a sufficiently abstract characterization to accommodate differences in usage of terms such as justice, justitia, dikaiosunê, etc. Yet it is characteristically human that we construct and maintain things together. Plato’s world is limited to city-states, but Plato gives us the idea of each doing/having their own as a core idea for determining each person’s share in common accomplishments. “To each their own” reason also plays a role in the work of al-Fārābi. But the range of interpretations of that idea becomes visible through the Nazi appropriation of the slogan. Another point of orientation is Aristotle’s distinction between distributive and corrective justice. From Cicero, finally, we get the thought that reflection on each person’s share might involve reflection on concentric circles of involvement.

The concept of kosmos did not play the leading role in Aristotle’s physics that it did in Pythagorean, Atomistic, Platonic, or Stoic physics. Although Aristotle greatly influenced the history of cosmology, he does not himself recognize a science of cosmology, a science taking the kosmos itself as the object of study with its own phenomena to be explained and its own principles that explain them. The term kosmos played an important role in two aspects of his predecessor’s accounts that Aristotle rejected: first, cosmogony and kosmopoiia, generation or creation of the kosmos; second, diakosmêsis, arranging of a plurality of kosmoi. Aristotle was extremely critical of accounts involving kosmopoiia and diakosmêsis and developed general dialectical strategies against them. In emphatically distinguishing his view from all his predecessors' (including Plato), he uses the terms ho ouranos (the heaven), to holon (the whole) and to pan (the totality) in preference to ho kosmos (the kosmos or world). There is usually no harm in speaking loosely of ‘Aristotle’s cosmology’ when referring to his concept of the order of nature and the ouranos. Nevertheless, Aristotle’s theoretical philosophy offers something very different from those of his predecessors, for whom kosmos was a keyword.

This chapter traces a genealogy of pneumatic cosmology, covering the Pythagoreans of the fifth century BCE, the Stoics of the third and second centuries BCE, the Jews writing in Alexandria in the first century BCE and the Christians of the first century CE. Starting from the early Pythagoreans, ‘breath’ and ‘breathing’ function to draw analogies between cosmogony and anthropogony – a notion ultimately rejected by Plato in the Timaeus and Aristotle in his cosmological works, but taken up by the Posidonius and expanded into a rich and challenging corporeal metaphysics. Similarly, the Post-Hellenistic philosopher and biblical exegete Philo of Alexandria approaches the cosmogony and anthropogony described in Genesis (1:1-3 and 1:7) through Platonist-Stoic philosophy, in his attempt to provide a philosophically rigorous explanation for why Moses employed certain terms or phrases when writing his book of creation. Finally, the chapter sees a determined shift in the direction of rejecting pneumatic cosmology for a revised pneumatic anthropogony in the writings of the New Testament: by appeal to the ‘Holy Spirit’ (πνεῦμα ἅγιον), early Christians effectively adapted the Stoic metaphysics of ‘breath’, with its notions of divine intelligence and bonding, to the ecclesiastical project of building a Christian community conceived of as the ‘body of Christ’.