Figures 5.1 and 5.2 give the simplest forms of the epicyclic and eccentric models respectively. In Figure 5.1 the planet (or sun or moon) (P) moves round the circumference of an epicycle, whose centre (C) itself moves round the circumference of what is called the deferent circle whose centre E is the earth. The sense of the movement of a planet on its epicycle is the same as that of the deferent circle, while for the sun and moon, which do not exhibit retrogradation, the two circles move in opposite senses.

Noted Augustine scholar J. H. S. Burleigh (d. 1985) once opined that Books 15–18 were “the least satisfactory section” of the entire ciu. Dei. While acknowledging that these words are comparative not superlative, this chapter suggests that there are good reasons for disagreeing with Burleigh’s assessment. Indeed, it contends that there is much to appreciate within this overtly “historical section” if one develops a sense for what Augustine is attempting within them.

Books 13 and 14, written around AD 418, are part of a broader set of Books 11–14 which deal with the origin of the earthly and heavenly cities. Books 13 and 14 were written in the midst of the Pelagian controversy but also sought to tackle an issue Augustine invested much time and energy in, from the very beginning of his ecclesiastical career. Furthermore, these two books can be read as commentaries on Genesis on the one hand, and as philosophical tractates critiquing Platonic and Stoic tenets on the other. And while Books 13 and 14 focus on the fall of Adam and its consequences, Augustine does use this opportunity to attack Pelagian positions explicitly in this context.

The predominant theme of ciu. Dei 2, which sets the course for Augustine’s critique of ancient Rome, is the disastrous influence of a religion without public moral teaching to offer. In exploring his treatment of that theme, we must first pause over the word ‘religion’, which is ours and not Augustine’s. ‘Religion and morality’ is the way we would naturally pose the question, and more commonly talk about morality without religion than about religion without morality. Augustine could also have expressed his question in our way. He uses the word ritus (plural), sometimes in phrases, as ritus sacri, ritus religionis, in ways that correspond sufficiently to our use of the term ‘religion’, and on one occasion he even refers to ‘religion and morality’ (ritibus moribusque; ciu. Dei 14.1). But he states the question in terms of the conduct of demons, really existing powers that are worshipped as gods in Roman religion, who have failed to provide the city with laws and its worshippers with moral instruction, and who have peremptorily demanded the homage of corrupting theatrical productions.

This chapter discusses the relation between causation and moral responsibility. We generally hold adult human beings morally responsible for their actions, yet those action are also events in the natural world, enmeshed in causal chains that extend backwards in time long before the agent’s birth. If the causes in those chains necessitate their effects, it would appear that we must either give up the view that humans are morally responsible for their actions, or embrace the paradoxical view that humans are morally responsible for actions necessitated by events over which they have no control. Tuozzo argues that Aristotle’s causal theory avoids this dilemma by recognising two distinct types of causal chain or nexus. In one of these, the links between cause and effect are indeed necessary, from beginning to end. But chains of this sort are necessarily finite, with a definite beginning and end. Each of these necessary, finite causal chains are also enmeshed in a different sort of causal nexus, one that does extend indefinitely into the past. But this sort of indefinite causal chain is possible only because it contains links that are not necessitated. This enables Aristotle to account for moral responsibility by locating the necessitating cause of a human action in the agent herself. Nonetheless, Tuozzo concludes, Aristotle’s theory does have the paradoxical implication that, although the state of the world at a given time does not necessitate all subsequent events, a complete description of it would, in principle, allow all subsequent events – including human actions – to be predicted.

This chapter argues that, for Aristotle, human emotions are both different from, and also importantly continuous with, the emotions experienced by non-human animals. On the one hand, the repertoire of emotions experienced by human beings differs significantly from the repertoire experienced by non-human animals. The difference stems from the fact that only human beings have reason. Some human emotions (for example, shame) require the possession of reason and hence cannot be experienced by non-human animals. Other human emotions have counterparts in non-human animals, but they differ from these counterparts because, when functioning correctly, they are guided by reason. For instance, the disposition to feel fear is reason-governed in a human being but not in an animal. On the other hand, in spite of these striking differences between human and animal emotions, Dow argues that the emotions also reveal an important continuity between human beings and other animals: both human and animal emotions are fundamentally capacities to respond with pleasure or pain to situations that are apparently good or harmful to the subject. In this sense, emotion plays a similar role in the lives of humans and non-human animals.

This chapter uses Aristotle’s account in the Nicomachean Ethics to reconstruct Eudoxus’ argument for the thesis that pleasure is the good. He sets out and explains Eudoxus’s argument from universal pursuit: pleasure must be the good because all animals pursue pleasure in all natural and fitting choices. Eudoxus’ naturalism is an important background assumption here. He assumes that each animal, by nature, successfully chooses in all situations what is good for itself. This allows him to move from an observation about the universal pursuit of pleasure to the claim that pleasure is a feature of all natural and good choices. The pleasure that features in such choices is overall pleasure. Thus, Eudoxus can allow that animals sometimes naturally choose things that are painful, provided that what they choose contains more pleasure than pain overall. Aufderheide ends by suggesting how Eudoxus might defend the claim that pleasure is not merely a good, but moreover the good. This is not to claim that pleasure is the only thing that is good, but rather that pleasure plays a unique role in relation to choice: it is the only thing that features in all natural and good choices as a good.

This chapter discusses Aristotle’s puzzling claim that ‘craft does not deliberate’ (Physics II.8). This claim is made in answer to an imagined objection: craft and nature cannot be analogous because craft-production involves deliberation. The claim is puzzling, as it seems obvious that certain craftsmen will need to deliberate if they are to do their jobs well. In response, Coope argues (following Sedley) that Aristotle is not denying that particular craftsmen deliberate. His point is rather that the craft itself does not deliberate. However, this response itself gives rise to a second puzzle: how is this claim (that the craft itself does not deliberate) relevant to defending Aristotle’s analogy between craft and nature? In response, Coope argues that Aristotle’s point is that it is the craft that explains the purposiveness of a process of craft-production and, analogously, it is the nature that explains the purposiveness of a natural process. In each case, the source of purposiveness is something that does not deliberate. The chapter ends by suggesting that this solution itself raises a new difficulty for Aristotle: can he give an analogous account of the purposiveness of those ordinary human intentional actions that are not cases of craft-production?

This chapter looks at Plato’s take on the nomos-phusis antithesis in his Laws. He argues that the goal of the Laws, of legislating in accordance with nature, should be distinguished from the much-studied idea of 'natural law' in two ways. First, in the relevant parts of the Laws, the focus is primarily the right way to conduct an activity, legislation, rather than its product (laws or law). Secondly, the Laws draws a comparison with other specialised or technical activities that can be performed well or badly, such as medicine or building. Legislation is natural, among other things, when it is undertaken in a certain ‘natural’ order, from the starting point of life to death. This order ensures that no stage of life is ignored during the legislative process and thus guarantees its comprehensiveness. Plato’s comparison between the legislator and other craftsmen presents a view of natural procedure within an art or profession: the craftsman is not subjected to constraints that are external to the subject matter and he is able to give full attention to the objectives and questions that belong to his craft. Finally, the legislation considered here is ‘natural’ without being underpinned by theology.

This chapter investigates the critique of anthropomorphism that we find in Xenophanes of Colophon and Heraclitus of Ephesus. Hesiod’s Theogony is assumed as background and as paradigm for the tendency to treat either the world’s components or gods generally as humanlike. With Xenophanes of Colophon we have the first and one of the fiercest attacks on such a kind of anthropomorphism, inasmuch as Xenophanes not only challenges anthropomorphism in traditional religion and myth but also intimates that at the root of religious beliefs and practices, among his fellow Greeks as well as among foreigners, is a motive of philautia, of self-love. Another strong early critique of anthropomorphism is found in Heraclitus of Ephesus, who curtly dismisses the idea of world-making by a god and stridently attacks certain traditional forms of religious worship. And yet neither thinker can avoid sliding into a particular kind of anthropomorphism, namely into what Mourelatos calls ‘epistemic anthropo-philautia’ – philautia understood not as the ‘self-love’ or ‘vanity’ an individual may show, but rather as the species-philautia we indulge in when we project upon the cosmos structures and forms that cognitively afford special intuitive appeal to us human beings.

According to Aristotle there is an important distinction between human beings and the rest of nature: while all other creatures develop as they do ‘necessarily or for the most part’, the development of human beings depends on their own efforts. This applies not only to their acquisition of technical and intellectual accomplishments, but to their character as well. Emotions or affections (pathē) play an important role in that development; they have an interesting ‘passive-cum-active’ character. Although their experience is not determined by choice, it is due to understanding and evaluating the particular situation. Reasoning is therefore in a way involved in the formation of human affections by habituation. The process of habituation determines not only how human beings act, but also how they feel. The affective part of the soul, though it is non-rational, is capable of ‘listening’ to reason more or less well and thereby the person acquires good or bad dispositions to act. Thus, in a human being, affections can be reasonable or unreasonable: The distinctive reason-responsiveness of the affections helps to explain why, despite certain natural predispositions, successful human development cannot simply be attributed to nature.

Christopher Rowe argues that Aristotle in the Eudemian Ethics develops a naturalised account of Socrates’s divine sign: even people lacking in practical wisdom, Aristotle proposes, can act appropriately, and achieve a kind of happiness, because of something divine in them. But this ‘something divine’ is not (as it is for Socrates) a private inner voice, rather a kind of well-naturedness. For Aristotle, goodness is natural. The goodness of human nature explains how it is possible to do the appropriate things even without reasoning, and even do so reliably. This offers Aristotle an answer to a puzzle about our relation to the natural world. Humans, he holds, are good by nature, yet he also holds fully virtuous human beings to be relatively rare: two claims that are hard to reconcile, given Aristotle’s usual view that what occurs ‘by nature’ occurs ‘always or for the most part’. By allowing there to be a level of decency that is achievable through well-naturedness, even by those who lack full virtue, Aristotle can answer this puzzle. If this decency is achieved by many people, then there is, after all, a kind of good human development that occurs by nature and occurs regularly.