This book presents novel formalizations of three of the most important medieval logical theories: supposition, consequence and obligations. In an additional fourth part, an in-depth analysis of the concept of formalization is presented - a crucial concept in the current logical panorama, which as such receives surprisingly little attention.Although formalizations of medieval logical theories have been proposed earlier in the literature, the formalizations presented here are all based on innovative vantage points: supposition theories as algorithmic hermeneutics, theories of consequence analyzed (...) with tools borrowed from model-theory and two-dimensional semantics, and obligations as logical games. For this reason, this is perhaps the first time that these medieval logical theories are made fully accessible to the modern philosopher and logician who wishes to obtain a better grasp of them, but who has always been held back by the lack of appropriate ‘translations' into modern terms.Moreover, the book offers a reflection on the very nature of logic, a reflection that is prompted by the comparisons between medieval and modern logic, their similarities and dissimilarities. It is thus a contribution not only to the history of logic, but also to the philosophy of logic, the philosophy of language and semantics.The analysis of medieval logic is also relevant for the modern philosopher and logician in that, being the unifying methodology used across all disciplines at that time, logic really provided unity to science. It thus presents a unified model of scientific investigation, where logic plays the aggregating role. (shrink)

My aim in this paper is to advance our understanding of medieval approaches to consciousness by focusing on a particular but, as it seems to me, representative medieval debate. The debate in question is between William Ockham and Walter Chatton over the existence of what these two thinkers refer to as “reflexive intellective intuitive cognition”. Although framed in the technical terminology of late-medieval cognitive psychology, the basic question at issue between them is this: Does the mind (or “intellect”) cognize its (...) own states via higher-order (or “reflexive”) representational states? Their debate is representative both because it highlights the central dialectical issues and alternatives at play in medieval discussions of consciousness generally and because it showcases the two main types of approach to consciousness one finds in the later medieval period, namely, those that explain consciousness in terms of intentionality (typically, higher-order intentionality), and those that understand consciousness as a non-intentional, sui-generis mode of awareness. (shrink)