ABSTRACTIn this paper, I explore the contrast drawn by Aristotle in two parallel passages of the Posterior Analytics between ‘signs’ and ‘demonstration’. I argue that while at APo. I.6 Aristotle contrasts demonstration proper with a deductively valid sign-syllogism, at APo. II.17 the contrast is rather between a demonstration proper and a deductively invalid sign-syllogism.

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)

Sweet Analytics, ‘tis thou hast ravish'd me,Bene disserere est finis logices.Is to dispute well logic's chiefest end?Affords this art no greater miracle?(Christopher Marlow, Doctor Faustus, Act 1,...

Sweet Analytics, ‘tis thou hast ravish'd me,Bene disserere est finis logices.Is to dispute well logic's chiefest end?Affords this art no greater miracle?(Christopher Marlow, Doctor Faustus, Act 1,...