Andrea Araf

In questo contributo prendo in esame la lettera di Leibniz a Christian Philipp del gennaio 1680. A sollecitare la redazione di questo scritto fu lo stesso Philipp, il quale chiese spiegazioni in merito alle implicazioni ateistiche della filosofia di Descartes menzionate da Leibniz durante un incontro. Leibniz rispose citando per intero un passo dei Principi di Filosofia (p. III, art. 47), nel quale Descartes afferma che la materia assume in successione tutte le forme possibili. Secondo Leibniz, questa proposizione contiene gravissime implicazioni teologiche che devono essere evitate ad ogni costo. La lettera a Christian Philipp è un esempio particolarmente significativo della stretta correlazione tra dottrine fisiche e teologiche che caratterizza i dibattiti filosofici della prima età moderna. Questo scritto, inoltre, rappresenta un’importante testimonianza del complesso rapporto che Leibniz intratteneva con il pensiero di Descartes. L’obiezione anticartesiana formulata nella lettera sarà infatti spesso ripetuta da Leibniz nel corso della sua carriera. Nella conclusione mi soffermo sulle due obiezioni che, all’epoca, i cartesiani Johann Rabel e Pierre-Sylvain Règis rivolsero all’interpretazione leibniziana di Principi di filosofia, p. III, art. 47.

The traditional notion of prime matter has always raised an epistemological puzzle: how can we have cognitive access to something completely indeterminate? I argue that Plotinus offers a striking approach to this problem, one that has been obscured by a longstanding misreading. Since Marsilio Ficino in 1492, scholars have taken matter as the implied subject of 2.4.11,35–8. This produces several difficulties of textual flow, obscurity and coherence. I contend that the subject is instead the soul. This reinterpretation solves the difficulties and restores Plotinus’ approach to the epistemological problem: matter can be grasped by analogy through the representation of a simultaneously contracting and expanding mass.

This article examines the sources of Plotinus’ doctrine of extension, a central aspect of his Platonic dualism whose origins have received little scholarly attention. This doctrine entails a distinction between two central concepts: the notion of body as primarily divisible or extended ‘mass’ (ὄγκος) and that of immanent form as secondarily divisible or extended quality (ποιότης). The article argues that, although Plotinus presents this doctrine as an interpretation of Plato, Timaeus 35a, its philosophical content is irreducible to the Timaeus, and that Plotinus rather employs, adapts, and develops concepts drawn from Aristotle. First, Plotinus’ notion of ‘mass’ finds conceptual and textual parallels in Aristotle’s Physics, especially in the discussions of place and continuous magnitudes (Books IV and VI). Second, Plotinus’ distinction between bodies and qualities as primarily and secondarily divisible or extended represents a sophisticated development of chapter 6 of the Categories, where Aristotle discusses quantity and distinguishes per se and accidental quantities. Finally, the article shows that Middle Platonic authors (Ammonius Saccas, Numenius) had already employed Aristotle’s distinction between per se and accidental quantities in their anti-Stoic polemics, and that Plotinus’ engagement with Aristotle is far more sophisticated.

In a problematic passage at the beginning of his treatise De Mixtione (I, 1.9–16), Alexander of Aphrodisias judges Chrysippus’ theory of total blending to be more paradoxical than two other paradoxical claims on mixture. Scholars understand these two claims either as a unitary position or as two distinct positions. In the latter case, they maintain that an emendation is necessary to make sense of the first claim. Through textual and philosophical analysis, this article shows that the claims represent two distinct positions—the realist view and Democritus’ reductionist account—and that no emendation is necessary. The article defends the transmitted text by explaining how Alexander can characterize the realist view as paradoxical despite endorsing it himself. To do so, it illustrates the meaning of ‘paradoxical’ in light of Alexander’s use of common notions (koinai ennoiai) as evaluative criteria and thoroughly connects the passage to the wider dialectical framework of the De Mixtione, thus reconstructing the rationale behind Alexander’s evaluation of each of these three positions as paradoxical.