Stoic Logic Allows Understanding a Priori Falsity in the Conditional

An issue to explain in cognitive science is nowadays the case of certain conditionals that people seem to deem as a priori false. Those conditionals appear to be false by virtue of semantics: the meanings of their antecedents and their consequents seem not to admit any link between them. This is a problem because, from the point of view of classical logic, they are not always false; there can be situations in which they are true (as classical logic provides, whenever their antecedents are false, those conditionals in entirety are true). There are contemporary frameworks explaining this phenomenon (e.g., the theory of mental models). However, this paper tries to make the point that the solution might be already in ancient philosophy: in particular, in Chrysippus’ logic. Thus, the paper describes in details (1) why those conditionals are controversial in classical logic and (2) the account that can be given for them from Chrysippus’ philosophy. That account is based mainly on the Stoic idea that the negation of the second clause of a conditional should not be compatible with its first clause.

Berkeley’s Stoic Notion of Spiritual Substances

For Berkeley, minds are not Cartesian spiritual substances because they cannot be said to exist (even if only conceptually) abstracted from their activities. Similarly, Berkeley’s notion of mind differs from Locke’s in that, for Berkeley, minds are not abstract substrata in which ideas inhere. Instead, a mind is a substance in a way consistent with the Stoic logic of the seventeenth-century Ramists on which Leibniz and Jonathan Edwards draw. The Stoic character of Berkeley’s philosophy is recognizable only when we see how it is based on a doctrine in which perceptions or ideas are intelligible precisely because they are always embedded in the propositions of a discourse or language.

The Metaphysics of Stoic Corporealism

The Stoics are famously committed to the thesis that only bodies are, and for this reason they are rightly called “corporealists.” They are also famously compared to Plato’s earthborn Giants in the Sophist, and rightly so given their steadfast commitment to body as being. But the Stoics also notoriously turn the tables on Plato and coopt his “dunamis proposal” that being is whatever can act or be acted upon, to underwrite their commitment to body rather than shrink from it as the Giants do. The substance of Stoic corporealism, however, has not been fully appreciated. This paper argues that Stoic corporealism goes beyond the dunamis proposal, which is simply an ontological criterion for being, to the metaphysics of body. This involves, first, an account of body as metaphysically simple and hence fundamental; second, an account of body as malleable and continuous, hence fit for blending (krasis di’ holou) and composition. In addition, the metaphysics of body involves a distinction between this composition relation seen in the cosmology, and the constitution relation by which the four-fold schema called the Stoic Categories proceeds, e.g. the relation between a statue and its clay, or a fist and its underlying hand. It has not been appreciated that the cosmology and the Categories are distinct — and complementary — explanatory enterprises, the one accounting for generation and unity, the other taking those individuals once generated, and giving a mereological analysis of their identity and persistence conditions, kinds, and qualities. The result is an elegant division of Plato’s labor from the Battle of Gods and Giants. On the one hand, the Stoics rehabilitate the crude cosmology of the Presocratics to deliver generation and unity in completely corporeal terms, and that work is found in their Physics. On the other hand, they reform the Giants and “dare to corporealize,” delivering all manner of predication (from identity to the virtues), and that work is found in Stoic Logic. Recognizing the distinctness of these explanatory enterprises helps dissolve scholarly puzzles, and harmonizes the Stoics with themselves.

Sociological Stoicism

This article initiates a conversation between sociological theory and the contemporary revival of Stoicism. Identifying four problems common to historical and contemporary incarnations of Stoicism and tracing them to their shared individualism, I contend that only a sociological Stoicism is viable. I then sketch this sociological Stoicism by redefining key Stoic terms in the collective register; outlining a Stoic logic of case selection; assessing the fit of redefined Stoic concepts and logic of case selection with Marxian, Weberian, and Bourdieuvian frameworks; and developing a Stoic research agenda. These exercises culminate in the proposal to significantly alter sociology’s methods and epistemology.

The ‘Age of Iron and Rust’ in Cassius Dio’s Roman History: Influences from Stoic Philosophy

This paper discusses the impact of Stoic philosophy on Cassius Dio’s imperial books of his Roman History. It is demonstrated how fundamental Stoic ideas influenced Dio’s constitutional discussions and the role of the emperor as in the Agrippa-Maecenas debate in book 52, and how Dio evaluated political environments as well as political developments in the Empire with inspirations from Stoic logic. Moreover, this paper argues that the iron age in his contemporary narrative from the emperor Commodus to Caracalla is also fundamentally an iron age on the basis of Stoic values.

Demonstration and the Indemonstrability of the Stoic Indemonstrables

Since Mates’ seminal Stoic Logic there has been uncertainty and debate about how to treat the term anapodeiktos when used of Stoic syllogisms. This paper argues that the customary translation of anapodeiktos by ‘indemonstrable’ is accurate, and it explains why this is so. At the heart of the explanation is an argument that, contrary to what is commonly assumed, indemonstrability is rooted in the generic account of the Stoic epistemic notion of demonstration (apodeixis). Some minor insights into Stoic logic ensue.

The Propedeutic of the Theory of Judgment in Ancient Philosophy from the Sophists to Plato’s Theaetetus

In the ancient epistemology, precisely stated definition of judgment (axioma) appears only in the 3rd century B.C. It was formulated by Chrysippus of Soli, the founder of the Stoic logic. However, on the other hand, the analysis of the extant utterances in which the knowledge had been objectified since the first Greek thinkers, allows us to state that the evolution of the theory of judgment was a long process. In this development, Greek epistemology had to deal with a number of problems connected with the object of the judgment –– knowledge, with the form of its objectification –– predication, and also with the predicates of the true and false judgment –– categories of “truth” (aletheia) and “falsehood” (pseudos). The first definition of the false judgement (logos pseudes) and the true judgment (logos alethes) can be found only in the late dialogue of Plato, Sophist, which delivers precisely established terminology of the theorem. Yet, such a definition could be formulated only when Greek epistemology re-defined the scope of the meaning of the key terms-concepts, aletheia and pseudos. The term-concept aletheia was identified with the term-concept being, functioning in the ontological-axiological sphere. On the other hand, pseudos did not mean false in the sense of negating the truth, but something, which is different than truth, is its imperfect copy. Thus, the pre-Platonic philosophy has not yet formulated the terminology in which predication of something inconsistent with the actual state of being, with the truth, could be verbalized. Often to express such a form of predication, a phrase “to utter things, which are not” was used. The other problem was connected with –– characteristic ofthe Greek language –– dual function of the verb to be/einai, which included both existential and truthful function. Accordingly, every utterance, in which the predicate was the verb einai or its derivates, was ex definitione a true predication –– “it spoke beings (things, which are).” In such a situation, there was noneed in epistemology to precisely define judgment as such, and to state the conditions which the true judgment hadto meet. The problem is definitely solved by Plato in his dialogue Theaetetus, in which the philosopher defines the object of the judgment, which is knowledge (however, its object is not stated yet) and introduces the project of verification of the utterances/opinion, thanks to which an opinion ––doxa can reach the status of judgment ––logos. An opinion needs to be verified with the dialectical procedures.

Chrysippus (c.280–c.206 BC)

The Greek philosopher Chrysippus of Soli was the third and greatest head of the Stoic school in Athens. He wrote voluminously, and in particular developed Stoic logic into a truly formidable system. His philosophy is effectively identical with ‘early Stoicism’.