At the beginning of the debate over free will, freedom is nowhere to be found. In the Hellenistic period, the question of human autonomy is not one of freedom (eleutheria) but instead, given the nature of the universe, what is “up to us” (eph’emin) and thus left to our choice (prohairesis). It is Cicero and the Epicurean poet Lucretius who first turn the debate into one specifically over man’s freedom from fate. But Cicero’s idea of the will’s libertas – its opportunity to conquer vice and win honor – is very different from that of Lucretius in De rerum natura, a text Cicero read and may even have edited. De fato, one of the last in his corpus, returns to the question of a libera voluntas explicitly to refute the Epicurean doctrine of the swerve (clinamen) and their abandonment of civic duty. For Cicero, free will is the locus of public virtue, the justification of “praise and honors,” and the power to strengthen ourselves against natural vice. Cicero’s letters reveal, in turn, that this technical treatise on fate has decidedly political stakes for the Roman Republic.

In this chapter, I examine how voluntas helps the young lawyer Cicero craft arguments and structure relationships with Roman clients, witnesses, and juries. In the De inventione and forensic speeches, we see his struggle to reconcile tradition with new intellectual tools. As he seeks to bring ratio more fully into Roman legal culture, voluntas plays a plural and ambiguous role. It is an instrument of rational inquiry, as in the competing schemata of criminal responsibility he examines in the De inventione. As it has always been in Roman law, voluntas is the desire of a legally relevant individual, emanating from and attributable to him alone – the marker of his agency and responsibility. So, too, however, is it used to signify the collective goodwill of an audience, which Cicero makes clear is the expert orator’s plaything. The “goodwill” sense of voluntas adds greatly to its durability in moral philosophy. While a sententia or iudicium pertain to a specific question, voluntas marks an ongoing choice or disposition, such as the will of a legislator, to be conserved. Cicero’s objectives for the law go largely unachieved in his time, but they expand Rome’s intellectual field of vision.

The treatise On Generation and Corruption (GC) consists of a general account of generation and corruption (offered in the first book) plus an elemental theory (advanced in the second book). This introduction explores the relation between these two pieces. The upshot of this exploration is that the unity of the treatise is stronger than it is often thought. Far from being a suboptimal amalgam of various pieces, the treatise is the best and most efficient way to fulfill the promise made at the outset, where an account of the nature and causes of generation and corruption is announced, including how they differ from other natural processes such as alteration and growth.

This essay explores the role that GC II 10 plays in the context of the treatise as a whole. It argues that while the rest of the treatise, up to and including GC II 9, explains generation and perishing by means of material and formal causes, GC II 10 provides the efficient and final causes, and thus brings the project announced at the outset of GC to completion. The essay analyses the arguments for the efficient cause of generation and corruption (identified with the sun’s annual course along the ecliptic) and its final cause (identified with a universal desire for the highest kind of being). For Aristotle, the best approximation to the being of imperishable substance which the sublunary sphere permits, given the nature of its constituents, is perpetual reproduction (for living things) and an endless cycle of reciprocal change (for elements). Finally, the essay illustrates how Aristotle’s fourfold scheme of causal explanations practically applies to generation and perishing in view of what Aristotle claims elsewhere about the unmoved mover and the gradation of being.

In GC II 5, Aristotle proceeds through a long and complicated argument against the view that there is a single primary body, concluding that a single simple body cannot function as the matter or origin of the other simple bodies. In doing so, he responds to a possible objection to his own account, defended in GC II 4, and confirms that each of the simple bodies is an origin for each of the others. This essay brings attention to the role of contrarieties in Aristotle’s refutation of theories that maintain a single primary body, either as the matter or the material origin of other simple bodies: given the role of contrarieties in explaining simple bodies, Aristotle finds that a single primary body is incompatible with the existence of change. By highlighting the role of contrarieties in explaining change, Aristotle leaves room for the primary contraries to function as a kind of matter, although the details of his account are not explored in GC II 5.

After arguing that each of the elements can come to be out of each of the three others, the bulk of GC II 4 presents and compares the speed and ease of three mechanisms by which the elements change into one another. While scholars have thought these three mechanisms are narrowly focused on individual changes, i.e., the three ways an element can change into each of the others, on my interpretation, the three mechanisms describe every possible complete cycle by which all four elements come to be, either singly or pairwise. Thus, I understand Aristotle’s interest in speed and ease as an interest in which mechanism generates all four elements most quickly and easily. My interpretation shows Aristotle builds on passages other scholars and translators have deemed textual oddities or mistakes and has the additional advantage of showing that Aristotle’s interest in the relative speed and ease of cycles of elemental transformation lays the groundwork for his metaphysical and scientific projects in GC II 10 and the Meteorology.

Aristotle’s longest and most comprehensive critical discussion of Empedocles’ natural philosophy occurs in GC II 6. He structures his criticism around four Empedoclean theses. (1) There are four kinds of elemental body and instances of these kinds do not change into one another. (2) Everything that comes to be by nature does so by chance. (3) Love and strife are the principles of natural bodily movement. (4) Soul is, or is constituted by, one or more of the four elemental bodies. I discuss Aristotle’s arguments against each of these theses in detail. Though Aristotle’s arguments are predominantly negative, we can view them as collectively constituting a sustained defense of the superiority of his preferred account. Aristotle’s natural philosophy centers on his novel understanding of nature as an internal principle and cause of movement and rest. I argue that the phenomena Empedocles is unable to explain adequately or endorse consistently are precisely the phenomena that Aristotle’s conception of nature is well-suited to explain.

In GC II 8, Aristotle shows that earth, water, air, and fire, are presented in every mixed body. Here Aristotle develops further the discussion of elemental mixtures started in GC II 7. He goes beyond anything done up to this point because the mixed bodies he is concerned with are not just the elemental mixtures discussed in GC II 7; rather, they are all the mixed bodies inhabiting the region around the center of the universe. Insofar as this region is the place where the natural processes of generation and corruption take place, GC II 8 prepares the grounds for the final section of the GC II (GC II 9-11).

In GC II 3, Aristotle gives an initial justification of three theses: (i) that there are four primary bodies; (ii) that these are earth, air, fire, and water; and (iii) that each is associated with two primary differentiae. Despite his laconic presentation, Aristotle offers an impressive variety of justifications for his main contentions: he appeals to combinatorial mathematics, to what is “in accordance with argument,” to empirical observation, and to his predecessors. I consider whether this chapter indicates that the primary bodies are not really elements; whether the “apparent simple bodies” Aristotle mentions are the primary bodies or something else; and how to understand the “fiery” and “airy” things that are not fire and air (respectively) but somehow like them. I find that the primary bodies are indeed genuine elements of sensible bodies for Aristotle; that the “apparent simple bodies” are the everyday counterparts of the elemental bodies; and that the contrast between fiery and airy things and fire and air is a contrast between the elemental bodies and their everyday counterparts.

In GC II 2, Aristotle discovers the contrarieties that constitute the principles of all perceptible bodies. They are the hot and the cold, the dry and the moist because they are the basic tangible contrarieties that interact as active and passive powers in a way that can result in a new affection. In GC II 2, Aristotle also attempts a reduction of all other tangible contrarieties to the basic four. I argue that the active/passive relation does not hold only between the two basic pairs of contrarieties but also within each pair. I compare the reduction of other contraries to the basic four with what Aristotle says in Meteor. IV. Despite minor differences and the wider scope of analysis in the latter work, Aristotle’s admirable effort to reduce the rich variety of tangible properties to a limited number of contraries and elements is the same.

GC II 7 supports Aristotle’s elemental theory, according to which the four elements possess a common matter that enables their inter-transformation, over the superficially similar Empedoclean one, by arguing that the former theory, and it alone, can accommodate the formation of homogenous stuffs like flesh and bone from the four elements. According to the interpretation offered here, these stuffs are mixtures in the sense spelled out in GC II 10, and appear to be exhibit the kind of strong uniformity that some interpreters have denied to Aristotelian mixtures. Special attention is devoted to bringing out the significance of elemental mixture for Aristotle’s twin projects in GC: understanding the causes of generation and destruction and establishing a theory of the elements. Explaining the formation of elemental mixtures is a crucial step in showing how the generation of more complex substances is possible and how the four elements, as he conceives them, function as elements of more complex substances.