When do things change? When do things have some characteristics? I try to answer these questions by looking at different solutions Plato and Aristotle presented in their works. The famous analysis of change from the second half of Plato’s Parmenides claims that change happens outside of time, at an “instant”. On the contrary, Aristotle in the Physics explicitly argues that all change occurs only in time. However, both Plato and Aristotle also provide other analyses of change. How to deal with (...) this variety of explanations and tensions between them? In this paper, I argue that if we differentiate between several kinds of change, most of Plato’s and Aristotle’s analyses provide a thorough insight into the nature of change. For processes such as locomotion, change occurs exclusively within time. For changes where both the initial and final states occur only in time, such as a transition from motion to rest, change takes place in the ‘now’. However, for changes where both the initial and final states occur in both time and in the ‘now’ – for example, a qualitative change from being white to not being white – change does not occur in time nor in the ‘now’, but instead happens instantaneously. (shrink)

This paper offers a reconstruction of Xenocrates’ theory of indivisibles which would not commit him to the idea of ‘jerky motion’ criticized by Aristotle in Physica VI, yet would perfectly square with Plato’s Timaeus, the basis of Xenocrates’ canon. Relying on Alexander’s, Porphyry’s, and Themistius’s accounts of his theory, as well on a detailed analysis of De lineis insecabilibus, I suggest that Xenocrates’ minima, contrary to what Aristotle implies, are not to be understood as more or less stable particulars, like (...) tiny chunks of matter, moving about or leaping in physical space from point A to point B. Yet Xenocrates’ minima do remain ‘physical’ and ‘corporeal’ in a more Platonic sense of these words, not presupposing any kind of leaping, jumping, or jerking. This explains why Xenocrates associated the sensible realm with one of the three Fates, namely Clotho. (shrink)

The present PhD dissertation aims to examine the relation between modality and change in Aristotle’s metaphysics. -/- On the one hand, Aristotle supports his modal realism (i.e., worldly objects have modal properties - potentialities and essences - that ground the ascriptions of possibility and necessity) by arguing that the rejection of modal realism makes change inexplicable, or, worse, banishes it from the realm of reality. On the other hand, the Stagirite analyses processes by means of modal notions (‘change is the (...) actuality of what is virtual insofar as it is virtual’). In other words: to grasp what change is, one has to resort to the modal idiom of potentialities, while the fact that there is change is indicative of the fact that nature is full of modal properties. -/- Aristotle’s modal and kinetic realism finds a negative in the figure of the Megaric Diodorus Kronus. The polemical situation of Greek philosophy has indeed the dialectical advantage of not opposing the Aristotelian position to a sui generis straw man. Both in its reduction of modal judgements to temporal quantifications and in its dissolution of the reality of the state-of-being-in-motion in favour of a cinematographic view of processes, the philosophical figure of reductionist antirealism embodied by Diodorus constitutes an alternative that takes the opposite view of Aristotle’s realism. -/- The present study is structured as a discussion between these two positions. In the face of Diodorus’ antirealist challenges, Aristotle articulates modal and kinetic considerations: the answers he gives to Diodorus’ puzzles thus provide valuable insight into his metaphysics. Moreover, the examination of Aristotle’s and Diodorus’ metaphysics, because of their insight and originality, will not fail to interest the philosopher concerned with the metaphysical foundations of modern physics, insofar as the entanglement between modalities and processes is nowadays at the core of mechanics (phase spaces, path integrals, etc.). (shrink)

After a brief introduction I compare accounts of what it is to say something I find in Plato, Frege and Grice, and I distinguish linguistic from practical meaning and words that signify things from ‘syncategorematic’ or ‘grammatical’ words. I then argue that the relation between a signifying word and what it signifies must be understood in terms of two complementary acts, already recognised in antiquity, quantifying and predicating. Discussing quantification, I show how problems about universals can be avoided by accepting (...) Aristotle's distinction between possible and actual existence. Discussing predication, I defend Aristotle's view that there are more forms of predication than one, and consider this issue in connection with non-mathematical discourse. (shrink)

This paper provides a short historical and systematic survey of parameters, problems, and proposals concerning the theoretical treatment of indivisible temporal boundaries throughout the ages. A very early trace of thinking about them is identified in Aristophanes’ comedy The Clouds. The approach of logicians in the late Middle Ages is placed in a broad context. Links of this topic to the issues of vagueness, modality, space and quantized time are discussed.

Cet article étudie la notion platonicienne d’instant. Je soutiens que dans leParménide, «maintenant» (nun) et «soudain» (exaiphnês) renvoient à la même entité, envisagée à partir des perspectives distinctes de l’Être éternel et du Devenir temporel. Cette interprétation complète et éclaire les notions platoniciennes de temps et d’éternité présentées dans leTimée. L’article met enfin en évidence le rôle décisif de la troisième déduction — où apparaît la notion d’instant — dans la compréhension de l’exercice dialectique duParménidedans son ensemble.