In the first book of the Prior Analytics, Aristotle sets out, for the first time in Greek philosophy, a logical system. It consists of a deductive system (I.4-22), meta-logical results (I.23-26), and a method for finding and giving deductions (I.27-29) that can apply in “any art or science whatsoever” (I.30). After this, Aristotle compares this method with Plato’s method of division, a procedure designed to find essences of natural kinds through systematic classification. This critical comparison in APr I.31 raises an (...) interpretive puzzle: how can Aristotle reasonably juxtapose two methods that differ so much in their aims and approach? What can be gained by doing so? Previous interpreters have failed to show how this comparison is legitimate or what important point Aristotle is making. The goal of this paper is to resolve the puzzle. In resolving this puzzle we not only learn more about the relationship be- tween division and the syllogistic in Aristotle. We will also learn something about the motivation for the syllogistic itself, by seeing the role that it plays in his philosophy of science. (shrink)

Scholars often assert that Plato and Aristotle share the view that discursive thought is internal speech. However, there has been little work to clarify or substantiate this reading. In this paper I show Plato and Aristotle share some core commitments about the relationship of thought and speech, but cash out TIS in different ways. Plato and Aristotle both hold that discursive thinking is a process that moves from a set of doxastic states to a final doxastic state. The resulting judgments (...) can be true or false. Norms govern these final judgments and, in virtue of that, they govern the process that arrives at those judgments. The principal norm is consistency. However, the philosophers differ on the source of this norm. For Plato, persuasiveness and accuracy ground non-contradiction because internal speech is dialogical. For Aristotle, the Principle of Non-Contradiction grounds a Doxastic Thesis that no judgment can contradict itself. For Aristotle, metaphysics grounds non-contradiction because internal speech is monological. (shrink)

The principle of bivalence (PB) states that every declarative sentence is either true or false, and the principle of excluded middle (PEM) states that one member of any contradictory pair must be true. According to the standard interpretation of Int. 9, PB fails for future contingents. Moreover, some standardists believe that PEM fails for pairs of contradictory future contingents, whereas other standardists attempt to rescue PEM by applying the method of supervaluations. I argue that PB and PEM are not suspended (...) and that the method of supervaluations fails to explain how PEM holds. I propose an interpretation of Int. 9 according to which neither PB nor PEM fails. (shrink)

En este trabajo planteo la pregunta de si la lógica de Aristóteles es o no una lógica formal. Respondo que, aunque las doctrinas contenidas en el Organon inauguren, efectivamente, la lógica formal, hay también buenas razones para pensar que Aristóteles no creía que la lógica fuese una disciplina que pudiera prescindir por completo del contenido. In this paper I discuss the question of whether Aristotle’s logic is a formal logic or not. I answer that, although the doctrines contained in the (...) Organon inaugurate indeed formal logic, there are also good reasons to think that Aristotle did not believe that logic was a discipline that ought to prescind completely from content. (shrink)

My dissertation is devoted to an examination of the resolution of fallacy in Plato's Euthydemus. It is a familiar claim that the Euthydemus champions Socratic argumentation over sophistical or eristic reasoning. No consensus however exists regarding either the nature or philosophical significance of Socrates’ treatment of the fallacies he confronts. I argue that a careful reading of the dialogue reveals that the Socratic response to fallacious reasoning is conducted at two different levels of philosophical sophistication. Socrates relies upon the resources (...) of Socratic dialectic in responding to sophisms due to ignorance of refutation. Insofar as Socratic dialectic is grounded in a grasp of the nature of genuine refutation, the objections it raises to false refutation are fully explanatory. On the other hand, Socrates employs various self-refutation arguments against theses which depend on false assumptions regarding the nature of predication---for example, the thesis that false speaking is impossible. It is however characteristic of Socratic dialectic that this method of examination cannot explain why the sophists’ theses are false. The Socratic response to fallacy in these cases is non-explanatory in this sense. On the other hand, these limitations on Socratic expertise are overcome in other passages in the dialogue which are replete with clues to the reader that point to a genuine explanation and resolution of the sophists’ arguments for their various theses. In particular, the reader is invited at every turn to modify, clarify, or reject various assumptions made by the brothers regarding the nature of predication. Here Plato implicitly relies on the results of what I call higher dialectic. This theory, which receives explicit formulation in the Sophist, is conceptually rich enough to expose and dispose of the various false assumptions upon which the sophists’ theses rest. I conclude that the Euthydemus is concerned to identify Socratic dialectic as only a part of philosophy, and to locate and strictly delimit its epistemological status as lying above eristic and the rhetorical arts, but below that of dialectic as that is conceived in the Republic and even later dialogues---thus anticipating the Sophist’s conception of Socrates as the practitioner of a ‘noble sophistry’, and the elenchus as a propaedeutic to philosophy, which purges the soul of false beliefs. (shrink)