Taking Per Martin-Löf’s constructive type theory as a starting-point a theory of assertion is developed, which is able to account for the epistemic aspects of the speech act of assertion, and in which it is shown that assertion is not a wide genus. From a constructivist point of view, one is entitled to assert, for example, that a proposition A is true, only if one has constructed a proof object a for A in an act of demonstration. One thereby has (...) grounded the assertion by an act of demonstration, and a grounding account of assertion therefore suits constructive type theory. Because the act of demonstration in which such a proof object is constructed results in knowledge that A is true, the constructivist account of assertion has to ward off some of the criticism directed against knowledge accounts of assertion. It is especially the internal relation between a judgement being grounded and its being known that makes it possible to do so. The grounding account of assertion can be considered as a justification account of assertion, but it also differs from justification accounts recently proposed, namely in the treatment of selfless assertions, that is, assertions which are grounded, but are not accompanied by belief. (shrink)

This essay aims to sharpen debates on the pros and cons of historical epistemology, which is now understood as a novel approach to the study of knowledge, by comparing it with the history of epistemology as traditionally pursued by philosophers. The many versions of both approaches are not always easily discernable. Yet, a reasoned comparison of certain versions can and should be made. In the first section of this article, I argue that the most interesting difference involves neither the subject (...) matter nor goal, but the methods used by the two approaches. In the second section, I ask which of the two approaches or methods is more promising given that both historical epistemologists and historians of epistemology claim to contribute to epistemology simpliciter . Using traditional problems concerning the epistemic role of perception, I argue that the historical epistemologies of Wartofsky and Daston and Galison fail to show that studying practices of perception is philosophically significant. Standard methods from the history of epistemology are more promising, as I show by means of reconstructing arguments in a debate about the relation between perception and judgment in psychological research on the famous moon illusion. (shrink)

There will be a few themes. One to get us going: expansion versus contraction. About an object, o, and the region, R, of space(time) in which o is exactly located,1 we may ask: i) must there exist expansions of o: objects in filled superregions2 of R? ii) must there exist contractions of o: objects in filled subregions of..

Taking Per Martin-Löf’s constructive type theory as a starting-point a theory of assertion is developed, which is able to account for the epistemic aspects of the speech act of assertion, and in which it is shown that assertion is not a wide genus. From a constructivist point of view, one is entitled to assert, for example, that a proposition A is true, only if one has constructed a proof object a for A in an act of demonstration. One thereby has (...) grounded the assertion by an act of demonstration, and a grounding account of assertion therefore suits constructive type theory. Because the act of demonstration in which such a proof object is constructed results in knowledge that A is true, the constructivist account of assertion has to ward off some of the criticism directed against knowledge accounts of assertion. It is especially the internal relation between a judgement being grounded and its being known that makes it possible to do so. The grounding account of assertion can be considered as a justification account of assertion, but it also differs from justification accounts recently proposed, namely in the treatment of selfless assertions, that is, assertions which are grounded, but are not accompanied by belief. (shrink)

In this paper I explore a famous part of Plato’s Theaetetus where Socrates develops various models of the mind (picturing it first as a wax tablet and then as an aviary full of specimen birds). These are to solve some puzzles about how it is possible to make a mistake. On my interpretation, defended here, the discussion of mistakes is no digression, but is part of the refutation of Theaetetus’s thesis that knowledge is “true doxa”. It reveals that false doxa (...) is possible only if there is a certain stock of abstract knowledge, conceptual knowledge, that is not awareness of the particular individual that is being described. The individual must be identified under some description, or seen as something of a certain kind. Error can only occur if the description applied misdescribes the situation, but then if it is to be applied falsely it must first have been known from somewhere else. So knowledge cannot be reduced to the application of descriptions to particulars, but is to be found in the prior possession of abstract descriptions that can be deployed in identifying particular individuals on the ground. (shrink)

In this article I offer an account of normative thought inspired by Plato's proposal in the Theaetetus that judgement is ‘speech spoken … silently.’ After arguing that force conventionalism is the speech act theory best suited for modeling dialogic inner speech, I close the article by sketching the picture of normative thought that results. Though I defend a particular theory of normative speech elsewhere, the core insights of this article can be used by other theorists as well. The arguments offered (...) here also serve as an important step forward for the more general program of using social speech to better understand thought. (shrink)

Scholars who have taken interest in Theaetetus' educational theme argue that Plato contrasts an inferior, even dangerous, sophistic education to a superior, philosophical, Socratic education. I explore the contrasting exhortations, methods, ideals and epistemological foundations of Socratic and Protagorean education and suggest that Socrates' treatment of Protagoras as educator is far less dismissive than others claim. Indeed, Plato, in Theaetetus, offers a qualified defence of both Socrates and Protagoras. Socrates and Protagoras each dwell in the middle ground between the extremes (...) presented in the dialogue's digression, which contrasts the life of the philosopher and the life of the courtroom orator. Both Socrates and Protagoras demonstrate a serious engagement with both politics and philosophy. Theodorus presents an educational option in which theory is divorced from politics while an ignoble sophistic education is presented as political but divorced from theory. Protagorean education, in Theaetetus, emerges as superior to a base sophistic education, though it remains inferior to Socratic education. (shrink)

Pāṇini's fourth century BC Sanskrit grammar uses rewrite rules utilizing an explicit formal language defined through a semi-formal metalanguage. The grammar is generative, meaning that it is capable of expressing a potential infinity of well-formed Sanskrit sentences starting from a finite symbolic inventory. The grammar's operational rules involve extensive use of auxiliary markers, in the form of Sanskrit phonemes, to control grammatical derivations. Pāṇini's rules often utilize a generic context-sensitive format to identify terms used in replacement, modification or deletion operations. (...) The context-sensitive rule format is itself defined using Pāṇini's more general method of auxiliary markers, the latter used to define many dozens of linguistic categories and rules controlling derivations of Sanskrit sentences through the manipulation of ‘non-terminal’ and ‘terminal’ symbols. This technique for controlling formal derivations was rediscovered by Emil Post in the 1920s and later shown by him to be ca... (shrink)

In thesophist (263e10–264b4), Plato distinguishes between two kinds of belief. On the one hand, there is a kind of belief that occurs “according to thinking” (κατὰ διάνοιαν), being “the completion of thinking” (διανοίας ἀποτελεύτησις). This kind is called ‘doxa.’ On the other hand, there is another kind of belief that occurs “through sense perception” (δι᾽ αἰσθήσεως). This kind is called ‘phantasia,’ perhaps best rendered as “appearing.”1 The purpose of this paper is to uncover the distinction between these two different kinds (...) of belief.2 What distinguishes these two kinds of belief is the believer’s understanding of the thing the belief is about, as a result of the way in which each kind of belief is .. (shrink)

This dissertation identifies and explains four major contributions of the Laws and related late dialogues to Plato's moral and political philosophy. -/- Chapter 1: I argue that Plato thinks the purpose of laws and other social institutions is the happiness of the city. A happy city is one in which the city's parts, i.e. the citizens, are unified under the rule of intelligence. Unlike the citizens of the Republic, the citizens of the Laws can all share the same true judgments (...) of value, and this unanimity explains the city's unity. Plato thinks that aiming at the city's happiness is justified, moreover, because a unified city contributes to the universe's order. -/- Chapter 2: In the Laws, Plato holds that the sick, poor, ugly, weak, but virtuous are happy, and that health, wealth, beauty, and strength benefit the virtuous but harm the vicious. Only in the Laws does Plato commit himself to all these claims simultaneously, and I explain how the moral psychology of the Laws permits Plato to maintain them coherently. -/- Chapter 3: I argue that, in the Laws, becoming virtuous is the same as becoming like God. Becoming like God does not require escape from the world of change as it does in the Theaetetus, however. Rather, becoming like God requires bringing "measure" or appropriate order to the world of change, especially to those entities over which we have the most control—our own souls. In the Laws, citizens achieve this order as they learn to be just and to understand the nature of reality. -/- Chapter 4: Unlike the Republic and Statesman, the Laws holds that obedience of the citizens to their laws should be effected, if possible, with rational persuasion. I argue that Plato wishes such persuasion to educate the citizens of the reasons for the laws. Understanding the laws' justification is the principal way in which citizens acquire the good judgment necessary for virtue. The city becomes more happy as the citizens progress in virtue, so rational persuasion is a necessary means to the lawgiver's overall aim. (shrink)