Abstract

My dissertation "Heidegger and the Origin of the Logical" treats the question, Is the world logical to begin with, or does man make it so? The question is raised within the context of Heidegger's thought, particularly with regard to his understanding of both the nature of logic and the thought of the founder of logic, Aristotle. In order to answer the question properly, it is necessary to do what Heidegger did not do: to explore in a Heideggerean manner the philosophical presuppositions of Aristotle's work on logic, freeing them from the misinterpretative horizon of Modern Logic's understanding of the nature of logic. As a result, the dissertation shows both how Modern Logic fails to understand its own origin, and the significance of that origin with regard to logic's relation to the world, to language, and to man. In short, the dissertation is a hermeneutic phenomenology of logic which opens up the possibility of seeing the poetic roots of logic. ;More specifically, the dissertation shows how logic is possible only if it presupposes the experience of the world and that which makes the world be what it is, its orderliness and composure . This is done by showing that: the possibility of the syllogism rests on the possibility of demonstration, which in turn rests on physis as the self-demonstrativeness of things in the world; implication and all logical connection owe their possibility to the difference between world and worldhood ; the origin of logic rests on the distinguishing of the worldly from the thingly in the meaning of identity qua physis; the formal structure of the syllogism is a function of the possibility of difference in the world, i.e., of physis; the apodeictic premise, far from being a modification of the categorical premise, is that from which the categorical premise is abstracted, and is itself a derivation from the problematic premise. Hence possibility and necessity are not modes of being along with actuality, rather they are the modes of the self-showing of things in the world; the ground of both possibility and necessity lies in the ontological possibility of man as he before whom the world is able to world. ;In order to demonstrate the above, a number of fundamental concepts of Modern Logic are interpreted and criticized: the distinction between being as existence and being as copula, the null class, the principles against self-contradiction and for self-identity, the paradoxes of implication, the superiority of symbolic notation as the 'language' of logic, and the laws of modal logic; furthermore a number of criticisms and clarifications of Aristotle's logic are proposed, among them some new modal syllogisms