Bobzien presents the definitive study of one of the most interesting intellectual legacies of the ancient Greeks: the Stoic theory of causal determinism. She explains what it was, how the Stoics justified it, and how it relates to their views on possibility, action, freedom, moral responsibility, moral character, fatalism, logical determinism and many other topics. She demonstrates the considerable philosophical richness and power that these ideas retain today.

Preliminaries: Terminology and Notation We may make a distinction between temporally definite and temporally indefinite sentences. ...

A full account of the philosophy of the Greek and Roman worlds from the last days of Aristotle until 100 BC. Hellenistic philosophy, for long relatively neglected and unappreciated, has over the last decade been the object of a considerable amount of scholarly attention. Now available in paperback, this 1999 volume is a general reference work which pulls the subject together and presents an overview. The History is organised by subject, rather than chronologically or by philosophical school, with sections on (...) logic, epistemology, physics and metaphysics, ethics and politics. It has been written by specialists but is intended to be a source of reference for any student of ancient philosophy, for students of classical antiquity and for students of the philosophy of later periods. Greek and Latin are used sparingly and always translated in the main text. (shrink)

At the heart of the Stoic theory of modality is a strict commitment to bivalence, even for future contingents. A commitment to both future truth and contingency has often been thought paradoxical. This paper argues that the Stoic retreat from necessity is successful. it maintains that the Stoics recognized three distinct senses of necessity and possibility: logical, metaphysical and providential. Logical necessity consists of truths that are knowable a priori. Metaphysical necessity consists of truths that are knowable a posteriori, a (...) world order according to certain metaphysical principles and natures that god crafts within the constraints of matter. Finally, what is providentially necessary is what occurs according to the chain of fate, but only once it is in process or past. -/- The method of the paper is a close reading of Diogenes Laertius 7.75, adducing broad textual evidence along the way, to show that the Stoic theory of modality embraces Philonian possibility, both that which is capable of being true as a matter of logical consistency, and that which is possible according to the bare fitness of the entity. What differentiates the Stoics from Philo is their additional commitment to possibility as opportunity, resisting the collapse of determinism into necessity. (shrink)

Controversy has surrounded the interpretation of the so-called 'Diodorean' and 'Chrysippean' conditionals of the Stoics. I critically evaluate and reject two interpretations of each of them: as expressing natural laws, and as strict conditionals. In doing so I engage with the work of authors such as Frede, Gould, Hurst, the Kneales, Mates, and Prior. I conclude by offering my own proposal for where these Stoic conditionals should be located on a 'ladder' of logical strength.

This monograph discusses the sources for ancient propositional logic, mainly in Sextus Empiricus and Diogenes Laertius bk. VII. It is argued that most of the sources in Sextus which have hitherto been taken to be sources for Stoic logic either do not report Stoic logic at all or report pre-Chrysippean Stoic logic. These texts report (in the first case) a group labelled the Dialecticians whose most prominent members were Diodorus Cronus and Philo or else (in the second case) early Stoic (...) logicians heavily influenced by the Dialecticians. The texts discussed concern the theory of signs, the theory of proof and the classifications of propositions and of arguments. (shrink)

In this paper I defend the existence of a Dialectical school proper against criticisms brought forward by Klaus Döring and by Jonathan Barnes. Whereas Döring claims that there was no Dialectical school separate from the Megarians, Barnes takes issue with my claim (argued for in “Dialektiker und frühe Stoiker bei Sextus Empiricus”) that most of the reports in Sextus on the dialecticians refer to members of the Dialectical school. Barnes contends that these dialecticians are in fact Stoic logicians. As against (...) Döring, I argue that the passage in Diogenes Laertius II 113 (first drawn attention to by David Sedley) which talks of a the Megarian Stilpo winning over disciples from the Dialecticians is not refuted by Döring’s arguments. It clearly shows that the Dialecticians and the Megarians at the time were taken to be different philosophical sects. As against Barnes I insist on the differences between the report in Ps.-Galen’s Historia 9 and the Sextan report on the theory of sign in AM VIII. These reports offer incompatible definitions of the indicative sign. Moreover, the classification of simple propositions reported by Sextus at AM VIII 96f. cannot be a truncated version of the (Stoic) list to be found in Diogenes Laertius VII 69f. since in Sextus’ report one of the three classes of simple propositions is labelled middle (meson). This is a certain sign that we are dealing with a triad, and hence that this list is meant to be complete. Therefore the classification found in Sextus and attributed to the dialecticians and the one in Diogenes Laertius reporting Stoic material do come from different sources. (shrink)

The master argument posits a metaphysical thesis: Diodorus does away with Aristotle’s dunamis understood as a power simultaneously oriented toward being and non-being and proclaims that possibilities that fail to actualize are simply nothing. My contention is that this claim is not a mere application of Diodorus’ contribution to modal logic. Rather, Diodorus creates an ontologico-temporal concept of possibility and impossibility. Diodorus envisions the future as the past that the future will become. Since what will have been can never be (...) the accomplishment of a possibility that did not obtain, and since the future is destined to become past, any futural possibility that doesn’t actualize is neither futural nor even possible. (shrink)

Adversus Mathematicos x is the second book dedicated by Sextus to the discussion of the physical doctrines put forward by dogmatic philosophers. An extensive section deals with Diodorus Cronus' arguments concerning movement.