This is a critical edition with introduction and indices of the Questiones libri Porphirii, a commentary on Porphyry__s Isagoge attributed to the fourteenth-century logician Thomas Manlevelt. Not... Show moreThis is a critical edition with introduction and indices of the Questiones libri Porphirii, a commentary on Porphyry__s Isagoge attributed to the fourteenth-century logician Thomas Manlevelt. Not much is known about Thomas Manlevelt, but his work is remarkable enough. Following in the footsteps of William of Ockham, Manlevelt stresses the individual nature of all things existing in the outside world. He radically challenges traditional medieval conceptions of the outside world. He applies Ockham__s Principle of Parsimony in an unscrupulous manner to do away with all entities not deemed necessary to preserve. In the end, Manlevelt even maintains that substance does not exist. The introduction to this edition sketches the historical and philosophical background of this logical-semantical text, in which individuality and the accidental play the key role. This edition contributes to our knowledge of the development of Ockhamism on the continent. Moreover, it confronts us with a hitherto hardly known thinker whose ideas may prove to be of more than just historical value. Show less
This thesis is on the history and philosophy of logic and semantics. Logic can be described as the ‘science of reasoning’, as it deals primarily with correct patterns of reasoning. However, logic... Show moreThis thesis is on the history and philosophy of logic and semantics. Logic can be described as the ‘science of reasoning’, as it deals primarily with correct patterns of reasoning. However, logic as a discipline has undergone dramatic changes in the last two centuries: while for ancient and medieval philosophers it belonged essentially to the realm of language studies, it has currently become a sub-branch of mathematics. This thesis attempts to establish a dialogue between the modern and the medieval traditions in logic, by means of ‘translations’ of the medieval logical theories into the modern framework of symbolic logic, i.e. formalizations. One of its conclusions is that, when properly understood within their own framework, the interest of medieval logical theories for modern investigations go beyond mere historical interest, but that a thorough conceptual analysis of such theories must be undertaken in order to avoid conceptual misprojections. While such translations of medieval into modern logic have been attempted before, the approach presented here is innovative in that attention is paid to the similarities as well as to the dissimilarities between the two traditions, and to what can be learned from the medieval masters for modern investigations in logic and semantics. Show less
