•  352
    Bobzien’s reply to a defamatory blogpost on her essay ‘Frege plagiarized the Stoics’ in which she is accused among other things of plagiarism (!), and deliberate deception, and which contains a large number of falsehoods. (This reply is a minor contribution to the discussion of 'Frege plagiarized the Stoics', simply setting the record straight. It contains no important philosophical content whatsoever.)
  •  258
    In this 2 1/2 page piece(ling) I introduce the terms 'to maleappropriate', 'maleappropriation', 'maleappropriator', etc., for a familiar phenomenon and pattern of behaviour, following a couple of autobiographical remarks and followed by some brief suggestions about how to handle the phenomenon. That's all. (Nothing of philosophical depth here.)
  •  111
    Determinism, Freedom, and Moral Responsibility brings together nine substantial essays on determinism, freedom, and moral responsibility in antiquity by Susanne Bobzien. The essays present the main ancient theories on these subjects, ranging historically from Aristotle followed by the Epicureans, the early Stoics, several later Stoics, and up to Alexander of Aphrodisias in the third century CE. The author discusses questions about rational and autonomous human agency and their compatibility wi…Read more
  •  4913
    In this extended essay, I argue that Frege plagiarized the Stoics --and I mean exactly that-- on a large scale in his work on the philosophy of logic and language as written mainly between 1890 and his death in 1925 (much of which published posthumously) and possibly earlier. I use ‘plagiarize' (or 'plagiarise’) merely as a descriptive term. The essay is not concerned with finger pointing or casting moral judgement. The point is rather to demonstrate carefully by means of detailed evidence that …Read more
  •  707
    Stoic logic and multiple generality
    Philosophers' Imprint 20 (31): 1-36. 2020.
    We argue that the extant evidence for Stoic logic provides all the elements required for a variable-free theory of multiple generality, including a number of remarkably modern features that straddle logic and semantics, such as the understanding of one- and two-place predicates as functions, the canonical formulation of universals as quantified conditionals, a straightforward relation between elements of propositional and first-order logic, and the roles of anaphora and rigid order in the regime…Read more
  •  17
    How to give someone Horns
    History of Philosophy & Logical Analysis 15 (1): 159-184. 2012.
    This paper discusses ancient versions of paradoxes today classified as paradoxes of presupposition and how their ancient solutions compare with contemporary ones. Sections 1–4 air ancient evidence for the Fallacy of Complex Question and suggested solutions, introduce the Horn Paradox, consider its authorship and contemporary solutions. Section 5 reconstructs the Stoic solution, suggesting the Stoics produced a Russellian-type solution based on a hidden scope ambiguity of negation. The difference…Read more
  •  701
    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. Some minor insights into Stoic logic …Read more
  •  715
    Intuitionism and the Modal Logic of Vagueness
    Journal of Philosophical Logic 49 (2): 221-248. 2020.
    Intuitionistic logic provides an elegant solution to the Sorites Paradox. Its acceptance has been hampered by two factors. First, the lack of an accepted semantics for languages containing vague terms has led even philosophers sympathetic to intuitionism to complain that no explanation has been given of why intuitionistic logic is the correct logic for such languages. Second, switching from classical to intuitionistic logic, while it may help with the Sorites, does not appear to offer any advant…Read more
  •  82
    ABSTRACT: English translation of the 2nd/3rd century Peripatetic Philosopher's Alexander of Aphrodisias commentary on Aristotle's non-modal syllogistic, i.e. on one of the most influential logical texts of all times. Volume includes introduction on Alexander of Aphrodisias and the early commentators, translation with notes and comments, appendices with a new translation of Aristotle's text, a summary of Aristotle's non-modal syllogistic and textual notes.
  •  828
    Stoic Sequent Logic and Proof Theory
    History and Philosophy of Logic 40 (3): 234-265. 2019.
    This paper contends that Stoic logic (i.e. Stoic analysis) deserves more attention from contemporary logicians. It sets out how, compared with contemporary propositional calculi, Stoic analysis is closest to methods of backward proof search for Gentzen-inspired substructural sequent logics, as they have been developed in logic programming and structural proof theory, and produces its proof search calculus in tree form. It shows how multiple similarities to Gentzen sequent systems combine with in…Read more
  •  99
    Analyticity, Balance and Non-admissibility of Cut in Stoic Logic
    with Roy Dyckhoff
    Studia Logica 107 (2): 375-397. 2019.
    This paper shows that, for the Hertz–Gentzen Systems of 1933, extended by a classical rule T1 and using certain axioms, all derivations are analytic: every cut formula occurs as a subformula in the cut’s conclusion. Since the Stoic cut rules are instances of Gentzen’s Cut rule of 1933, from this we infer the decidability of the propositional logic of the Stoics. We infer the correctness for this logic of a “relevance criterion” and of two “balance criteria”, and hence that a particular derivable…Read more
  •  694
    Gestalt Shifts in the Liar Or Why KT4M Is the Logic of Semantic Modalities
    In Bradley Armour-Garb (ed.), Reflections on the Liar, Oxford University. pp. 71-113. 2017.
    ABSTRACT: This chapter offers a revenge-free solution to the liar paradox (at the centre of which is the notion of Gestalt shift) and presents a formal representation of truth in, or for, a natural language like English, which proposes to show both why -- and how -- truth is coherent and how it appears to be incoherent, while preserving classical logic and most principles that some philosophers have taken to be central to the concept of truth and our use of that notion. The chapter argues that, …Read more
  •  799
    The Stoics on Hypotheses and Hypothetical Arguments
    Phronesis 42 (3): 299-312. 1997.
    ABSTRACT: In this paper I argue (i) that the hypothetical arguments about which the Stoic Chrysippus wrote numerous books (DL 7.196) are not to be confused with the so-called hypothetical syllogisms" but are the same hypothetical arguments as those mentioned five times in Epictetus (e.g. Diss. 1.25.11-12); and (ii) that these hypothetical arguments are formed by replacing in a non-hypothetical argument one (or more) of the premisses by a Stoic "hypothesis" or supposition. Such "hypotheses" or su…Read more
  •  764
    Pre-Stoic Hypothetical Syllogistic in Galen
    The Bulletin of the Institute of Classical Studies 57-72. 2002.
    ABSTRACT: This paper traces the evidence in Galen's Introduction to Logic (Institutio Logica) for a hypothetical syllogistic which predates Stoic propositional logic. It emerges that Galen is one of our main witnesses for such a theory, whose authors are most likely Theophrastus and Eudemus. A reconstruction of this theory is offered which - among other things - allows to solve some apparent textual difficulties in the Institutio Logica.
  •  380
    ABSTRACT: A brief critique of Bruno Haas’ interpretation of Kant’s categories of practical reason and a reply to his criticism of my paper 'Die Kategorien der Freiheit bei Kant' ('Kant's Categories of Freedom').
  •  111
    Propositional Logic in Ammonius
    In Helmut Linneweber-Lammerskitten & Georg Mohr (eds.), Interpretation und Argument, Koenigshausen & Neumann. 2002.
    ABSTRACT: This paper collects the evidence in Ammonius' surviving works for elements of a propositional logic, coming to the conclusion that Ammonius had a theory of hypothetical syllogisms in the tradition of Aristotle and the Peripatetics, with Platonic elements mixed in, and using some Stoic elements, but not a propositional logic in the narrower sense as we find it in Stoic logic.
  •  532
    Determinism and freedom in stoic philosophy
    Oxford University Press. 1998.
    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.
  •  105
    Early Stoic Determinism
    Revue de Métaphysique et de Morale 4 (4): 489-516. 2005.
    ABSTRACT: Although from the 2nd century BC to the 3rd AD the problems of determinism were discussed almost exclusively under the heading of fate, early Stoic determinism, as introduced by Zeno and elaborated by Chrysippus, was developed largely in Stoic writings on physics, independently of any specific "theory of fate ". Stoic determinism was firmly grounded in Stoic cosmology, and the Stoic notions of causes, as corporeal and responsible for both sustenance and change, and of effects as incorp…Read more
  •  65
    A greek parallel to Boethius' de hypotheticis syllogismis
    Mnemosyne 55 (3): 285-300. 2002.
    In this paper I present the text, a translation, and a commentary of a long anonymous scholium to Aristotle’s Analytics which is a Greek parallel to Boethius’ De Hypotheticis Syllogismis, but has so far not been recognized as such. The scholium discusses hypothetical syllogisms of the types modus ponens and modus tollens and hypothetical syllogisms constructed from three conditionals (‘wholly hypothetical syllogisms’). It is Peripatetic, and not Stoic, in its theoretical approach as well as its …Read more
  •  2781
    ABSTRACT: This paper serves two purposes: (i) it can be used by students as an introduction to chapters 1-5 of book iii of the NE; (ii) it suggests an answer to the unresolved question what overall objective this section of the NE has. The paper focuses primarily on Aristotle’s theory of what makes us responsible for our actions and character. After some preliminary observations about praise, blame and responsibility (Section 2), it sets out in detail how all the key notions of NE iii 1-5 are in…Read more
  •  599
    The Combinatorics of Stoic Conjunction
    Oxford Studies in Ancient Philosophy 40 157-188. 2011.
    ABSTRACT: The 3rd BCE Stoic logician "Chrysippus says that the number of conjunctions constructible from ten propositions exceeds one million. Hipparchus refuted this, demonstrating that the affirmative encompasses 103,049 conjunctions and the negative 310,952." After laying dormant for over 2000 years, the numbers in this Plutarch passage were recently identified as the 10th (and a derivative of the 11th) Schröder number, and F. Acerbi showed how the 2nd BCE astronomer Hipparchus could have cal…Read more
  •  446
    Logic: The Megarics
    In Keimpe Algra & et al (eds.), The Cambridge History of Hellenistic Philosophy, Cambridge University Press. 1999.
    ABSTRACT: Summary presentation of the surviving logic theories of Philo the Dialectician (aka Philo of Megara) and Diodorus Cronus, including some general remarks on propositional logical elements in their logic, a presentation of their theories of the conditional and a presentation of their modal theories, including a brief suggestion for a solution of the Master Argument.
  •  906
    Wholly Hypothetical Syllogisms
    Phronesis 45 (2): 87-137. 2000.
    ABSTRACT: In antiquity we encounter a distinction of two types of hypothetical syllogisms. One type are the ‘mixed hypothetical syllogisms’. The other type is the one to which the present paper is devoted. These arguments went by the name of ‘wholly hypothetical syllogisms’. They were thought to make up a self-contained system of valid arguments. Their paradigm case consists of two conditionals as premisses, and a third as conclusion. Their presentation, either schematically or by example, varie…Read more
  •  772
    ABSTRACT: Stewart Shapiro recently argued that there is no higher-order vagueness. More specifically, his thesis is: (ST) ‘So-called second-order vagueness in ‘F’ is nothing but first-order vagueness in the phrase ‘competent speaker of English’ or ‘competent user of “F”’. Shapiro bases (ST) on a description of the phenomenon of higher-order vagueness and two accounts of ‘borderline case’ and provides several arguments in its support. We present the phenomenon (as Shapiro describes it) and the ac…Read more
  •  277
    The paper presents a new theory of higher-order vagueness. This theory is an improvement on current theories of vagueness in that it (i) describes the kind of borderline cases relevant to the Sorites paradox, (ii) retains the ‘robustness’ of vague predicates, (iii) introduces a notion of higher-order vagueness that is compositional, but (iv) avoids the paradoxes of higher-order vagueness. The theory’s central building-blocks: Borderlinehood is defined as radical unclarity. Unclarity is defined b…Read more
  •  365
    Boethius in Ciceronis Topica (Review) (review)
    Journal of Roman Studies 79 263. 1989.
  •  3621
    Did Epicurus discover the Free-Will Problem?
    Oxford Studies in Ancient Philosophy 19 287-337. 2000.
    ABSTRACT: I argue that there is no evidence that Epicurus dealt with the kind of free-will problem he is traditionally associated with; i.e. that he discussed free choice or moral responsibility grounded on free choice, or that the "swerve" was involved in decision processes. Rather, for Epicurus, actions are fully determined by the agent's mental disposition at the outset of the action. Moral responsibility presupposes not free choice but that the person is unforced and causally responsible for…Read more
  •  1412
    ABSTRACT: This paper discusses the Stoic treatment of fallacies that are based on lexical ambiguities. It provides a detailed analysis of the relevant passages, lays bare textual and interpretative difficulties, explores what the Stoic view on the matter implies for their theory of language, and compares their view with Aristotle’s. In the paper I aim to show that, for the Stoics, fallacies of ambiguity are complexes of propositions and sentences and thus straddle the realms of meaning (which is…Read more