After over a decade of playing in the dirt and wading knee-deep in the elements, I've figured a few things out.

Aristotle's Material Elements is the result. Drafts of any of the chapters are available upon request. The current outline of the book is below.

Part I: Preliminaries

1. Chapter 1. Why the elements? Objectives and methodology

Chapter 1 begins by motivating the study of Aristotle’s material elements. The chapter situates the study of material elements and corresponding texts, De Caelo 3-4 and On Generation and Corruption 2, within the broader project of Aristotle’s science of nature, and limits the scope of the investigation within the remainder of the book. Next, the chapter briefly highlights the objectives of the book. The chapter concludes with two ideas that will organize the remainder of the book. The first of these, that Aristotle’s theory of motion for sublunary bodies permits motion in the categories of substance, quantity, quality, and place, is developed.

2. Chapter 2. Simple bodies and elements: Aristotle’s stoicheia

Chapter 2 examines the second idea that will organize the remainder of the book by defending the claim that Aristotle has three ways of thinking about ‘elements’ (stoicheia). In the literature, there is a disagreement regarding Aristotle’s use of the term for element, stoicheion. Readers of Aristotle have variously found textual evidence that it means one of three things: (1) principles of a logical sort, such as form, matter, and privation; (2) the primary contraries, which are hot, cold, wet, and dry; and (3) the simple bodies, which are fire, air, water, and earth. This chapter shows that the three interpretations are not mutually incompatible, but rather, point to methodological differences in various areas of inquiry.

Part II: Substantial change: Principles and elements of simple bodies

3. Chapter 3. The elemental transformations in On Generation and Corruption 2.4: Interpretations and problems

Chapter 3 begins with an overview of the elemental transformations in On Generation and Corruption 2.4, and establishes an interpretation of the text that makes sense of the three ways in which Aristotle takes simple bodies to be generated from one another. The second half of the chapter explains why the elemental transformations are problematic, and introduces three standard interpretations found in the literature. The chapter shows that none of the three standard interpretations can make sense of the elemental transformations because none of them can consistently explain why simple bodies are unified, why generation is different from alteration, and why opposites are involved in substantial change.

4. Chapter 4. Principles in Physics 1.7-9 and On Generation and Corruption 1.3

Chapter 4 provides a preliminary to solving the problem of elemental transformation by making the case that Aristotle, in fact, has three ways of thinking about matter. The chapter identifies a distinction implicit in Physics 1.7-9 between matter as a subject for predication and matter as a persisting substratum that is potentially a generated entity. The chapter then applies this distinction to a problem for the generation of simple bodies that Aristotle sets out in the closing of On Generation and Corruption 1.3. Against the defenders of prime matter, it defends the claim that the matter that is ‘the same’ is a subject for predication, whereas the matter that is ‘different’ is the primary contraries.

5. Chapter 5. Elemental structure and transformation: Substantial change

Chapter 5 (9,863 words) applies the distinctions made in Chapter 4 in order to develop an account of elemental structure that can coherently explain the generation of simple bodies from one another. The chapter defends the view that each simple body possesses one primary contrary as form and the other as its matter. Furthermore, it defends the view that matter is needed as a subject that underlies changes between opposites; this subject is an artifact of language, rather than the metaphysically robust concept found in defenses of prime matter. The chapter notes that the three interpretations rejected in Chapter 3 get something right: each of them appeals to ‘matter’, in one of the three senses described in Chapter 4.

Chapter 5 concludes with a brief Appendix. The Appendix briefly responds to a common objection to treating simple bodies as substances, which is found in Metaphysics Z. The Appendix shows that simple bodies do not fulfill the criteria for substance-hood in Metaphysics Z because they are not species of a genus, but nonetheless, can be unified in the same way as natural entities other than living things.

Part III: Primary and non-primary contraries: The powers of simple bodies

6. Chapter 6. Qualities and the primary contraries

Chapter 6 begins by arguing that the contraries Aristotle takes to be ‘primary’ in On Generation and Corruption 2.2 – hot, cold, wet, and dry – are powers of bodies. Next, the chapter examines Aristotle’s argument in GC 2.2 in order to show that there are two ways in which other contraries relate back to primary contraries. Other qualitative powers of bodies ‘reduce’ to the four primary contraries, but this requires the presence of all four contraries; only compound bodies possess the other qualities. Contraries that are not qualitative, such as rare-dense and heavy-light, ‘follow from’ the primary contraries, which means that the existence of a body is sufficient for possessing them. The chapter finishes by examining the relationship between primary contraries and characteristics that are available to sensation; it concludes that in the category of quality, the only features possessed by simple bodies are their primary qualities as well as the tangible and visual characteristics that follow from them.

7. Chapter 7. Quantity and Place

Chapter 7 examines the features of bodies that Chapter 6 showed to ‘follow from’ the primary contraries. Chapter 7 begins by pointing out Aristotle’s commitment to contraries in quantity and place and examining the relationship between these two categories. Next, the chapter confirms that the contraries heavy-light and rare-dense are powers of bodies; they are needed to explain why the positions up-down and the relations of magnitude, complete-incomplete, are non-arbitrary. The chapter concludes by briefly sketching the relationships between heavy-light, rare-dense, and the primary contraries.

Part IV: Locomotion and nature: The activities of simple bodies

8. Chapter 8. Natural motion and rest: Elemental nature in Physics 8.4

Chapter 8 turns to the natural motions of simple bodies by examining the relationship between natural locomotion and nature, as set out in Physics 8.4. The chapter begins by setting out a problem for the natural locomotion of simple bodies, and shows that Aristotle resolves it by confirming that simple bodies possess a nature. The chapter then defends the view that the nature of a simple body is a two-sided principle of both motion and rest. The nature of a simple body differs from that of self-movers because simple bodies are active while at rest in their own places; thus, the nature of a simple body is an active principle of rest and a passive principle of being moved. Furthermore, simple bodies are only moved naturally when their motion is a result of generation.

9. Chapter 9. Proper place and form in De Caelo 4.3

Chapter 9 argues that the project of De Caelo 4.3 is to explain why heavy and light bodies have the proper places that they do in order to confirm that locomotion is natural rather than arbitrary. The chapter provides a close study of Aristotle’s arguments in De Caelo 4.3 and shows that, in order for these arguments to succeed, Aristotle must be treating the form of a body as its quantitative form or external boundary rather than its degree of heaviness or lightness.

10. Chapter 10. Locomotion, quality, matter, and form in De Caelo 4

Chapter 10 makes the case that, in addition to the quantitative boundaries of a body, a consideration of quality is necessary in order to make sense of Aristotle’s account of locomotion and the arrangements of the simple bodies in De Caelo 4. The chapter shows, first, that actualization of quantity and quantity is necessary in order for locomotion to occur, and second, that Aristotle is aware that he must appeal to qualities in order to complete his account of heaviness and lightness. The chapter then appeals to the relationship between heavy-light and hot-cold-wet-dry to make sense of Aristotle’s puzzling claims about form and matter relations in De Caelo 4. The relationships between form and matter in De Caelo 4 are consistent with those introduced in the account of elemental transformations in Chapter 5, which points toward consistency between the texts.

11. Chapter 11. Teleology and identity: Complications and limitations

Chapter 11 begins by arguing that the nature of a simple body, as set out in Physics 8.4, can also be explained by an appeal to the primary contraries of On Generation and Corruption 2.1-4. The difference is that On Generation and Corruption 2.1-4 ignores bodies as they exist in nature, and hence their natural ends; the activity of a simple body is being at rest in its own place, and this is also its good. Next, the chapter examines the difference between the good for a body and the good of it; for a simple body, resting in its own place is a precondition for its contribution to the cosmic good, imitating the continuous and circular locomotion. The fact that bodies can return upon themselves in a cycle raises questions for the identity of bodies, and the chapter argues that a numerically identical portion of a simple body differentiated by the time of its existence, rather than its actual place. The chapter concludes by summarizing how the objectives of the book have been achieved.