Parts of Animals (PA) I.5 sends a strong message that the parts of the animal body are to be studied for the sake of the substance, the whole animal. If, as Aristotle suggests, it is the lowest or ‘indivisible’ species which are the substances, then we should study the parts of animals at this level. Yet many of the parts of animals are common to several species, so explaining them for each species would be repetitive and tiresome. We find thus in the PA two opposed explanatory tendencies: one ‘upwards’ toward the more common and greater simplicity and another ‘downwards’ toward the ultimate species and greater complexity. Aristotle’s proposed solution is to account for the various bodily parts at a general level and to descend to the species only when the parts differ significantly. In this chapter I discuss some difficulties for Aristotle’s solution.

The introduction briefly presents the text of the Parts of Animals and its history. It also provides an overview of the contents and philosophical questions that emerge from the text.

Aristotle’s understanding of natural objects as matter-form compounds raises important questions about how this hylomorphic view applies to living beings. More specifically:

1. (1) Is the form of living compounds ‘pure,’ that is essentially independent of matter, or ‘true-gritty,’ that is, essentially matter-involving?

2. (2) In his standard view, the form is prior to matter and the compound. But how can the form of living compounds meet this priority requirement if it is ‘true-gritty’?

3. (3) If, by contrast, the form of living compounds is ‘pure,’ how can it be the principle of material and changeable living compounds?

I argue that in De Partibus Animalium (PA), too, forms of living compounds are ‘true-gritty.’ They are also, however, prior to living compounds and their matter. PA offers evidence for a distinction between the type of matter that is essential to form and that of living compounds, which is not essential to but posterior to the form.

This chapter seeks to trace the history of On the Parts of Animals (hereafter PA) and the impact it had up to the Byzantine era and Michael of Ephesus, the first systematic commentator of Aristotle’s biological works. The first section examines a variety of works and passages until Galen’s time, delving deeper into the case of the ps.-Aristotelian On Breath. The second section focuses on Galen’s On the Usefulness of the Parts: Despite the fact that Galen argues that this treatise is part of the tradition of the PA, it emerges that Aristotelian zoology is discussed in late antiquity and the Middle Ages based on the study of other zoological treatises (or their epitomes) and not of the PA. The third section examines Michael’s commentary and especially his comments on the marrow and the brain. It is shown that Michael’s scholiastic activity contributes genuinely and substantially to the circulation of Aristotle’s thought in philosophical circles of the time.

Contracts awarded to brewers suggest the existence of local beer monopolies. However, the beer industry was a very decentralised sector, involving many brewers, as well as full- and part-time sellers supplying local markets. Such local networks were difficult for the state to penetrate, hence the use of local intermediaries who were themselves active in the industry. The fiscal contracts concerned the administration of state revenues derived from the village beer industry. Their most significant component was the farming of a craft and sales tax. In addition, contractors were involved with the distribution of state-supplied barley. A comparison with bakers shows that these artisans were not supplied with wheat, which could be profitably exported. The motivation for the sale of state barley was thus the conversion of revenue in kind into cash. Royal breweries existed, but their significance is unclear, and private individuals and temples owned breweries as well. Temples were, moreover, frequently the lessors of contracts, underscoring their role in the Ptolemaic economy and fiscal system. Missing variables complicate the assessment of the impact of the institutions on economic performance.

In this chapter, I argue that the first book of the Parts of Animals (PA) expresses a form of realism about animal species. While the claim that Aristotle was a realist about species may seem obvious to those coming to the PA from the Metaphysics, the current view among specialists is that Aristotle’s zoology was not working with a concept of species. Some have even gone so far as to avoid translating eidos as “species” throughout his zoological writings. In contrast to this, I argue: first, that indivisible species constitute the ousiai of Aristotle’s zoology; and, second, that the aim of Aristotelian zoological division is to identify and organize the features specified in the definition of those species. The latter (epistemological) claim is explicit in the discussion of division in PA I 2–3, while the former (ontological) claim is advanced in PA I 4.

This chapter considers the place of the four books of the Parts of Animals (PA) within Aristotle’s envisaged sequence of biological writings. It argues that PA I belongs integrally with II–IV (rather than being a self-standing theoretical essay) and that the entire project of PA I–IV presupposes key theoretical and factual discoveries made in the Historia Animalium (HA), contra the ‘Balme hypothesis’ according to which HA postdates the explanatory treatises and represents a more advanced stage of inquiry. Finally, it shows that the mantra “being is prior to coming-to-be” (which governs the PA–GA axis) has important implications for our understanding of the explanations in PA II–IV. It concludes with some remarks on the overall structure of Aristotle’s biological corpus.

In PA I.5, Aristotle encourages his audience to engage in a novel kind of philosophy: the scientific inquiry into animals and plants. What Aristotle is exhorting his readers to do, biology, is newly and originally conceived, but the literary technique employed – protreptic speech – is one of the oldest and most traditional kinds of philosophical discourse. In his earlier popular dialogue the Protrepticus, Aristotle had defended and promoted the Academic conception of philosophy and its preoccupation with theoretical and mathematical sciences such as astronomy by discussing the clarity of such sciences and the excellence of their objects. In the later protreptic to biology, he adapted these earlier arguments, arguing that biology also has excellent objects and offers a kind of clarity that may even surpass astronomy. These arguments turn out to be part of a general rhetorical strategy for comparing and rank-ordering sciences that was theorized in the Topics and Rhetoric.

This chapter focuses on those parts of animals that are deformed, useless, harmful, or ‘weird,’ and that thereby challenge Aristotle’s teleological view that the sublunary world and the animals in it are beautiful on the grounds that they are functional, and that they are therefore worthy of our study as well. My account will present three different types of teleological failure that Aristotle identifies in the production processes of animals with such ‘bad’ parts, one of which attributes ‘genuine’ mistakes or oversights to the formal natures crafting these animals. The chapter argues that especially this third type of mistake signals a methodological weakness in the explanatory project of the Parts of Animals as a whole, namely that it overextends Aristotle’s theory of natural teleology to features that could have been explained more satisfactorily by reference to chance or necessity alone.