Aristotle: Physics

Within the general discussion of space and its dimensionality, Aristotle's position is of the greatest relevance, as one will have the opportunity to argue and discuss in this article.

In Physics 2.4–6, Aristotle offers an account of things that happen “by luck” and “spontaneously”. Many of these things are what we might think of as “lucky breaks”: cases where things go well for us, even though we don’t expect them to. In Physics 2.5, Aristotle illustrates this idea with the case of a man who goes to the market for some reason unrelated to collecting a debt he is owed. While he is there, this man just so happens to (...) run into his debtor and get his money back—which is what he “wanted” all along. This case has a number of features that have proved puzzling. Most notably, Aristotle seems to think that while “it happened accidentally to him to come and to do this for the sake of getting the money”, nevertheless the man “did not come for the sake of this”—though he “would have”. What must such a proceeding be like to be described in these ways? Physics 2.4–6 makes several important moves towards answering this question. One of them—among the earliest and seemingly a foundational one—is the claim that “for the sake of something are as many things as could be done by thought and by nature”. The aim of this paper is to identify the role that this claim plays in Aristotle’s account of spontaneous proceedings. It defends two main claims. First, Aristotle’s suggestion that spontaneous proceedings could be done by nature and by thought is the product of a more general strategy. His approach is to sketch an intuitive pattern of explanation for proceedings that happen for the sake of something in the ordinary—non-spontaneous—way, and then to try to extend that model to the case of things that do so spontaneously, preserving as much of it as possible. Applying this strategy reveals that whereas nature and thought in fact function as efficient causes of ordinary proceedings that are for the sake of something, this cannot be the case in spontaneous ones. Instead, nature and thought could function as their causes. Second, I argue that Aristotle’s implementation of this strategy is rooted in his account of causation and especially Physics 2.3’s list of “modes” of causes. When he claims that spontaneous proceedings “could” be done by nature and by thought, he is saying that nature and thought are their efficient causes in capacity. In the practical case, spontaneous proceedings are caused by agents who have certain capacities, connected with their desires and abilities. In the right circumstances, these agents would actively exercise those capacities in acting for the sake of a given end. (shrink)

Even though Aristotle speaks often about language, his remarks do not fall within the province of any given discipline, let alone belong to the same subject matter or amount to a πραγματεία of their own. Rather, they are somewhat scattered across the Aristotelian corpus and are to be gleaned from a vast array of texts, including ethical and political writings (where language plays a remarkable role in shaping human sociability), treatises on natural history (where Aristotle outlines the physiology of phonation (...) in some animals such as birds and human beings), books on the soul (where Aristotle describes how language is intertwined with perception, imagination and thought) and works on dialectics, poetics and rhetoric (where linguistic expression is described as a powerful means of both persuasion and deception). Accordingly, «Le langage. Lectures d’Aristote» elects to study Aristotle’s understanding of language and its workings by asking relevant Aristotelian texts only those questions these texts answer – either by themselves or in conjunction with one another. -/- Quelque nombreuses et quelque influentes qu'elles soient par ailleurs, les vues d'Aristote sur le langage se caractérisent à la fois par leur hétérogénéité et par leur marginalité. Sans faire nulle part du langage et de la signification l'objet d'une investigation autonome et méthodique, Aristote multiplie les remarques et les digressions à leur sujet, que ce soit dans ses écrits d'éthique et de politique ou dans ses traités d'histoire et de philosophie naturelle, ou encore dans ses manuels de dialectique, de poétique et de rhétorique. Face à l'abondance de ces matériaux et aux difficultés qu'ils présentent du fait de s'offrir au lecteur en ordre quelque peu dispersé, «Le langage. Lectures d'Aristote» fait le choix d'indexer l'étude du langage chez Aristote sur des passages précis du corpus en ne posant aux textes aristotéliciens d'intérêt linguistique que les questions auxquelles ces mêmes textes - tantôt pris isolément, tantôt mis en relation les uns avec les autres - apportent une réponse. (shrink)

On propose ici de clarifier ce qu’Anaximandre entendait par « le divin » et ce qu’il appelait des « dieux ». À partir d’une réévaluation des sources anciennes, on soutient que cette enquête peut aider à comprendre son modèle cosmologique et le problème des cataclysmes dans son système. Trois hypothèses sont avancées à cette fin : [i] que dans Physique, III, 4, 203b3 15, le syntagme τὸ ἄπειρον renvoie à une notion concrète de substrat infini ; [ii] que dans ce (...) même passage, Aristote n’a probablement pas attribué aux philosophes de la nature – y compris Anaximandre – la thèse selon laquelle τὸ ἄπειρον est divin, mais plutôt la thèse selon laquelle ils comprennent le divin comme étant immortel et impérissable ; [iii] qu’Anaximandre, en supposant que « les astres célestes » sont des dieux, admettrait qu’ils naissent mais ne se détruisent pas – ce qui réfuterait l’idée d’un cataclysme universel chez lui. En conclusion, l’étude discute en quoi consisterait la gouvernance cosmique de τὸ ἄπειρον dans un univers divisé en trois niveaux et propose que cette gouvernance viendrait du fait que τὸ ἄπειρον possède un mouvement éternel. (shrink)

Aristotle's theory of eternal continuous motion and his argument from everlasting change and motion to the existence of an unmoved primary cause of motion, provided in book VIII of his Physics, is one of the most influential and persistent doctrines of ancient Greek philosophy. Nevertheless, the exact wording of Aristotle's discourse is doubtful and contentious at many places. The present critical edition of Ishaq ibn Hunayn's Arabic translation (9th c.) is supposed to replace the faulty edition by A. Badawi and (...) aims at contributing to the clarification of these textual difficulties by means of a detailed collation of the Arabic text with the most important Greek manuscripts, supported by comprehensive Greek and Arabic glossaries. (shrink)

Physics I 6 addresses the question of the number of principles and motivates the need for an underlying principle in addition to the contrary ones argued for in chapter 5. Physics I 6 ends in aporia about whether there are two or three principles, an aporia which is resolved with Aristotle’s own account in I 7. This chapter focuses on two issues. First, it explores how Aristotle’s arguments for contrary and underlying principles give rise to the aporia. Second, it discusses (...) Aristotle’s puzzling attitude towards, and use of, materialist views in I 6 and, more generally, in book I. Though Aristotle brings out deep tensions between his own hylomorphic conception and materialism, he also seems to downplay them for the purposes of arguing for an underlying principle. I suggest that this is a result of trying to motivate a hylomorphic conception of natural substance from within a more familiar materialist framework. (shrink)

This contribution offers an interpretation of the last half of chapter 1 of book 5 of Aristotle’s Physics in the form of a commentary. Among other things, it attempts an explanation of why Aristotle calls the termini of changes ‘something underlying’ (ὑποκείμενον) and ‘something not underlying’ (μὴ ὑποκείμενον). It also provides an analysis of Aristotle’s argument for the claim that what is not simpliciter does not change in the light of this interpretation.

Aristotelian commenters have long noted an apparent contradiction between what Aristotle says in Posterior Analytics I.2 and Physics I.1 about how we obtain first principles of a science. At Posterior 71b35–72a6, Aristotle states that what is most universal (καθόλου) is better-known by nature and initially less-known to us, while the particular (καθ’ ἕκαστον) is initially better-known to us, but less-known by nature. At Physics 184a21-30, however, Aristotle states that we move from what is better-known to us, which is universal (καθόλου), (...) to what is better-known absolutely, which is particular (καθ’ ἕκαστον). This paper turns to two of Aristotle’s most notable medieval commentators—Albertus Magnus and Thomas Aquinas—to resolve this apparent contradiction. The key to Thomas and Albert’s solutions, we will argue, is a twofold distinction between a sense-perceptive and scientific universal, and the particulars as sensed individuals and as differentiating attributes. Our Synthetic treatment of these distinctions contributes to the ongoing scholarly effort to understand the Stagyrite’s complex theory of knowledge. (shrink)

In Physics 4.11, Aristotle says that changes are continuous because magnitude is continuous. I suggest that this is not Aristotle’s considered view, and that in Generation and Corruption 2.10 Aristotle argues that this leads to the unacceptable consequence that alterations can occur discontinuously. Physics 6.4 was written to amend this theory, and to argue that changes are continuous because changing bodies are so. I also discuss the question of Aristotle’s consistency on the possibility of discontinuous alterations, such as freezing.

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, cosmogeny 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 he 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. (shrink)

I offer a fresh interpretation of the dialectical strategy of Physics 2.8’s arguments that things in nature happen for the sake of something. Whereas many recent interpreters have concluded that these arguments inevitably beg the question against Aristotle’s opponents, I argue that they constitute a careful attempt to build common ground with an opponent who rejects Aristotle’s basic worldview. This common ground, first articulated in the famous Winter Rain Argument, takes the form of an intriguing pattern of reasoning: that natural (...) proceedings that happen in a given manner always or for the most part do not do so by chance. (shrink)

The essay studies Aristotle’s critique of Parmenides in the light of the Heideggerian account of Platonic-Aristotelian metaphysics as an approach to being in terms of beings. Aristotle’s critique focuses on the presuppositions of the Parmenidean thesis of the unity of being. It is argued that a close study of the presuppositions of Aristotle’s own critique reveals an important difference between the Aristotelian metaphysical framework and the Parmenidean “protometaphysical” approach. The Parmenides fragments indicate being as such in the sense of the (...) pure, undifferentiated “is there” —as the intelligible accessibility of meaningful reality to thinking, prior to its articulation into determinate beings. For Aristotle, by contrast, “being itself” has no other plausible meaning than “being-something-determinate as such”, which itself remains equivocal. In this sense, Aristotle can indeed be said to conceive being in terms of beings, as the being-ness of determinate beings. (shrink)

The main aim of my paper is to analyse Aristotle’s theory of language in the context of his Physics I.1 and via an analysis and an interpretation of this part of his Physics I try to show that (i) the study of human language (logos) significantly falls within the competence of Aristotle’s physics (i.e. natural philosophy), (ii) we can find the results of such (physical) inquiry in Aristotle’s zoological writings, stated in the forms of the first principles, causes and elements (...) of the human speech (logos) and (iii) the analogies (Phys. 184b13-14) made by Aristotle at the very end of the first chapter make better sense if we consider them in the broader context in which Aristotle recognizes language as a complex natural phenomenon we are born into and which has to be not only biologically, but also socially developed through our lives. Hence, I aim towards a more naturalistic reading of Aristotle’s views on language. (shrink)

The difficulties often attributed to prime matter hold for all hylomorphic accounts of substantial change. If the substratum of substantial change actually persists through the change, then such change is merely another kind of accidental change. If the substratum does not persist, then substantial change is merely creation ex nihilo. Either way matter is an empty concept, explaining nothing. This conclusion follows from Aristotle’s homoeomerity principle, and attempts to evade this conclusion by relaxing the constraints Aristotle imposes on elementhood, generation, (...) and substrata all fail, and even the minimal constraints imposed by the Problem of Material Constitution are enough to generate the dilemma. -/- Aristotle resolves this dilemma in Physics I.9 by postulating pure potentiality-for-substance as the substratum of substantial change. Because the substratum persists, substantial change is not creation ex nihilo, but because it does not persist actually it is not a kind of accidental change. Aristotle uses this approach to solve the Problem of the Mixt and the Problem of Material Constitution without weakening his constraints on elementhood, generation, or substrata. This pure potentiality approach must be carefully distinguished from other ‘traditional’ or ‘prime matter’ views that posit some actuality for the substratum of substantial change, and it is best understood in light of the analogy found at Metaphysics Θ.6. Pure potentiality-for-substance can do the work needed in a substratum for substantial change because Aristotle is able to ground the identity, existence, and characterization of the substratum in the corrupting and generating substances rather than the substratum itself. (shrink)

The belief that Aristotle opposes potency (dunamis) to actuality (energeia or entelecheia) has gone untested. This essay defines and distinguishes forms of the Opposition Hypothesis—the Actualization, Privation, and Modal—examining the texts and arguments adduced to support them. Using Aristotle’s own account of opposition, the texts appear instead to show that potency and actuality are compatible, while arguments for their opposition produce intractable problems. Notably, Aristotle’s refutation of the Megarian Identity Hypothesis applies with equal or greater force to the Opposition Hypothesis. (...) For Aristotle, then, potency and actuality are compatible. (shrink)

This paper reconstructs the relationship between the now, motion, and number in Aristotle to clarify the nature of the now, and, thereby, the relationship between motion and time. Although it is clear that for Aristotle motion, and, more generally, change, are prior to time, the nature of this priority is not clear. But if time is the number of motion, then the priority of motion can be grasped by examining his theory of number. This paper aims to show that, just (...) as numbers are generated by the soul, time is not presupposed by motion, but emerges through the soul’s articulation of motion. Time is co-constituted by the soul and motion. The now is the key to understanding both the contribution of motion and soul to the being of time. The now is part of the soul’s articulation of motion, and sets the stage for an act that distinguishes a unit from its underlying motion. The now, then, sets up an abstraction by which the soul generates the temporal number from motion. Reconstructing this account of abstraction allows us to formulate more strongly Aristotle’s claim to the ontological dependence of time on motion. The paper then gives a systematic overview of the relationships between the now and number in order to address the question of whether the now might be extended. It closes with an examination of the possibility that motion depends on time, and how universal time is possible. (shrink)

Aristotle’s most fundamental distinction between changes and other activities is not that ofMetaphysicsΘ.6, between end-exclusive and end-inclusive activities, but one implicit inPhysics3.1’s definition of change, between the activity of something incomplete and the activity of something complete. Notably, only the latter distinction can account for Aristotle’s view, inPhysics3.3, that ‘agency’—effecting change in something, e.g. teaching—does not qualify strictly as a change. This distinction informsDe Anima2.5 and imparts unity to Aristotle’s extended treatment of change inPhysics3.1-3.

Journal Name: Apeiron Issue: Ahead of print.

In Physics I.8, Aristotle outlines and responds to an Eleatic argument against the reality of change. I defend a new reading according to which the argu- ment assumes Predicational Monism, the claim that each being can possess only one property. In Phys. I.2, Aristotle responds to Predicational Monism, which he attributes to the Eleatics; I argue that he uses this response to distinguish coin- cidental from non-coincidental becoming, a distinction he employs in Phys I.8 to resolve the argument against the (...) reality of change. The Eleatics’ acceptance of Predicational Monism, I argue, explains why this distinction is unavailable to them. (shrink)

This paper has two main goals: first, it reconstructs Aristotle’s account of measurement in his Metaphysics and shows how it connects to modern notions of measurement. Second, it demonstrates that Aristotle’s notion of measurement only works for simple measures, but leads him into a dilemma once it comes to measuring complex phenomena, like mo-tion, where two or more different aspects, such as time and space, have to be taken into account. This is shown with the help of Aristotle’s reaction to (...) one of the problems Zeno’s dichotomy paradox raises: Aristotle implicitly employs a complex measure of motion when solving this problem, while he explicitly characterizes the measure of motion as a simple measure in his Physics. (shrink)

Of Aristotle’s core terms, potency (dunamis) and actuality (energeia) are among the most important. But when we attempt to understand what they mean, we face the following problem: their primary meaning is movement, as a source (dunamis) or as movement itself (energeia). We therefore have to understand movement in order to understand them. But the structure of movement is itself articulated using these terms: it is the activity of a potential being, as potent. This paper examines this hermeneutic circle, and (...) works out a strategy for reading Aristotle based on his conception of our epistemological predicament. This hermeneutic approach helps us gain access to the phenomena of movement and its sources (potency, and energeia). The paper closes with a review of the conceptual resources we deploy to think about movement: homogeneity, space and time, impulse, relativity, the blend of sameness and difference, and being and non-being. Showing that Aristotle uses none of these clears the landscape for a fresh inquiry into his account of movement. (shrink)

The Middle Included is a systematic exploration of the meanings of logos throughout Aristotle’s work. It claims that the basic meaning is “gathering,” a relation that holds its terms together without isolating them or collapsing one to the other. This meaning also applies to logos in the sense of human language. Aristotle describes how some animals are capable of understanding non-firsthand experience without being able to relay it, while others relay it without understanding. Aygün argues that what distinguishes human language, (...) for Aristotle, is its ability to both understand and relay firsthand and non-firsthand experiences. This ability is key to understanding the human condition: science, history, news media, propaganda, gossip, utopian fiction, and sophistry, as well as philosophy. Ömer Aygün finds Aristotle’s name for this peculiar but crucial human ability of “gathering” both experiences is logos, and this leads to a claim about the specificity of human rationality and language. (shrink)

O presente trabalho visa demonstrar como a relação entre corpo e alma são indispensáveis para o viver. Para tanto, considera a tese de que o ser animado é uma substância composta de matéria e forma, que também pode ser analisada sob a perspectiva de potência e ato. Neste sentido, o trabalho inicia com a compreensão sobre o que é uma substância, qual tipo de substância é o ser vivo para, em seguida, mediante as definições de alma presentes no livro Β (...) do De Anima, perceber como se dá a relação entre corpo e alma e porque tal relação é necessária ao viver. (shrink)

Aristotle opens his discussion of time in Physics 4.10-14 with a puzzle, an argument which purports to show that time does not exist, since its only parts – the past and future – do not exist. He does not discuss the puzzle again, and so we are left with the question of how he would or could solve it. A full solution would involve not only a justification of realism about time, but also an account of why the puzzle arises, (...) what must be corrected to prevent it from arising, and how much of our pre-theoretical picture of time survives these adjustments. This paper argues that we can provide such a solution by (i) distinguishing between two ways of being committed to the reality of past, present, and future, and (ii) examining Aristotle’s remarks in Physics 4.12 on the notions of being in time and being surrounded by time. (shrink)

My topic is the fundamental Aristotelian division between the animate and the inanimate. In particular, I discuss the transformation that occurs when an inanimate body comes to be ensouled. When nutriment is transformed into flesh it is first changed into blood. I argue that blood is unique in being, at one and the same time, both animate and inanimate; it is inanimate nutriment in actuality (or in activity) and animate flesh in potentiality (or in capacity). I provide a detailed exposition (...) of these manners of being (covering individual substances, artifacts, and mixtures), apply these insights to the case of blood, and then argue that blood's curious status is central to understanding hylomorphism in living organisms. (shrink)

_ Source: _Volume 60, Issue 1, pp 88 - 126 The dominant interpretation of Metaphysics Θ.8 commits Aristotle to the claim that the heavenly bodies’ eternal movements are not the exercises of capacities. Against this, I argue that these movements are the result of necessarily exercised capacities. I clarify what it is for a heavenly body to possess a nature and argue that a body’s nature cannot be a final cause unless the natural body possesses capacities that are exercised for (...) the sake of its nature qua form. This discussion yields a better understanding of what capacities are, what explanatory work capacities do, and what it is to possess a nature. (shrink)

The article deals with the oldest criticism of Anaximander’s monism, for which we have evidence, found in John Philoponus’ commentary on the first book of Aristotle’s Physics . Philoponus’ argumentation is analytically examined and explained, its premises brought to light and its conclusions evaluated. It is shown how his inquiry, although anticipating modern discussions about the classification of Anaximander’s doctrine in terms of ‘monism’ and ‘pluralism’, differs from the contemporary approach to the problem when it comes to both results and (...) methodology. (shrink)

The aim of the present article is to consider the shortcomings of the physicalist rainfall example set forth by Aristotle in Physics II.8. I first outline the ancient physicalist account of the coming-to-be of natural organisms and the accompanying rejection of the teleological character of such processes. Then I examine the rainfall example itself. The fundamental difficulty is that rainfall does not appear to have a proper nature. Hence it is not natural in the strict sense and cannot be used (...) in arguments either for or against natural teleology. Rainfall can at most have an end in a weak sense, which makes it inadequate as a paradigm. Furthermore, the physicalist conception of action for an end is itself flawed. I argue that they construe it anthropomorphically and falsely presuppose a symmetry between coming-to-be and ceasing-to-be. I would like to thank Hasse Hamalainen and Marcin Karas for looking at earlier drafts of this paper. I am also especially grateful for the numerous remarks and suggestions of three anonymous referees. (shrink)

Aristotle offers several arguments in Physics viii.8 for his thesis that, when something moves back and forth, it does not undergo a single motion. These arguments occur against the background of a sophisticated theory, expounded in Physics v—vi, of the basic structure of motions and of other continuous entities such as times and magnitudes. The arguments in Physics viii.8 stand in a complex relation to that theory. On the one hand, Aristotle evidently relies on the theory in a number of (...) crucial steps. Yet in other steps he seems to contradict or misapply the theory. This situation offers the occasion to examine Aristotle’s views about some fundamentals in the metaphysics of motion, while also raising questions about the unity of the text which has come down to us as the Physics. (shrink)

In this paper, I examine Aristotle's notion of potentiality as it applies to the beginning of life. Aristotle’s notion of natural kinēsis implies that we should not treat the entity at the beginning of embryonic development as human, or indeed as the same as the one that is born. This leads us to ask: When does the embryo turn into a human? Aristotle’s own answer to this question is very harsh. Bracketing the views that lead to this harsh answer, his (...) theory of kinēsis still gives us reason for searching for a replacement answer. Aristotle’s own work unfortunately gives us no help in finding this answer. (shrink)

In Physics, Aristotle starts his positive account of the infinite by raising a problem: “[I]f one supposes it not to exist, many impossible things result, and equally if one supposes it to exist.” His views on time, extended magnitudes, and number imply that there must be some sense in which the infinite exists, for he holds that time has no beginning or end, magnitudes are infinitely divisible, and there is no highest number. In Aristotle's view, a plurality cannot escape having (...) bounds if all of its members exist at once. Two interesting, and contrasting, interpretations of Aristotle's account can be found in the work of Jaako Hintikka and of Jonathan Lear. Hintikka tries to explain the sense in which the infinite is actually, and the sense in which its being is like the being of a day or a contest. Lear focuses on the sense in which the infinite is only potential, and emphasizes that an infinite, unlike a day or a contest, is always incomplete. (shrink)

This paper presents Aristotle’s method of understanding the first principles of natural things in the Physics I.1 and analyzes the three stages of which this method consists. In the Physics I.1, Aristotle suggests that the natural proper route which one has to follow in order to find out the first principles of natural things is to proceed from what is clearer and more knowable to us to what is more knowable and clear by nature. In the Physics I.1, the terms (...) καθόλου and καθ΄ ἕκαστα are not used in their usual meaning. This paper examines the Physics I.1 in comparison with the Posterior Analytics II. 19 in order to elucidate the meaning of καθόλου in the first chapter of Aristotle’s Physics. Furthermore, it reaches the conclusion that the structure of the natural world to which we belong determines the structure and the form of our knowledge. On the one hand, natural things are composite and, on the other hand, perception is involved in the initial grasping of natural things as composites. Thus, since perceptual knowledge is more accessible to us than any other kind of knowledge it is natural to reach knowledge of simple things, i.e., of the principles, starting our inquiry with the composites. (shrink)

This paper explores Plato and Aristotle 's responses to the pre-Socratic philosopher Parmenides, who paradoxically said that there is no such thing as non-being, and no such things as change. I argue that Plato’s response would have been good enough to defeat the claim in a debate, thereby remedying the political aspects of the Parmenides problem. However, Aristotle ’s answer is required to answer some additional philosophical and scientific aspects. Plato's Sophist is a very difficult dialogue to understand; seeing it (...) in light of Aristotle 's discussion of the same topic helps to explain the complexities of what his teacher Plato wrote. (shrink)

In his Tractatus de proportionibus, Thomas Bradwardine describes some devices consisting of a magnet and pieces of iron, in order to put his rule of motion to the test. These devices, or similar ones, are also found in the Questiones super libros Physicorum of Nicole Oresme, and in three works by Blasius of Parma, namely the Questiones de ponderibus, the Questiones super libros Physicorum and the Questiones circa Tractatum proportionum. In this paper, I describe these devices, while examining the theory (...) of magnetism that is in use and I analyse how the arguments on magnets demarcate the field of application of the rule of motion. (shrink)