medieval logic, January 2007, and those of the Square of Opposition International Congress, June 2007, for stimulating and helpful discussion on earlier versions of this paper, and also the useful suggestions of the two anonymous referees.
Using a short excerpt from Anselm’s Responsio as an example, this paper tries to present logical reconstruction as a special type of exegetical interpretation by paraphrase that is subject to (adapted) hermeneutic maxims and presumption rules that govern exegetical interpretation in general. As such, logical reconstruction will be distinguished from the non-interpretative enterprise of formalization and from the development of theories of logical form, which provide a framework in which formalization and reconstruction take place. Yet, even though logical reconstruction is dependent on methods of formalization, it allows us to use formal methods for the analysis and assessment of natural language texts that are not readily formalizable and is thus an important tool when it comes to applying the concepts and methods of formal logic to such texts.
various topics dogmatists classify under “logic”. It does contain such an inquiry, but as part of a bigger project to undercut the objection from dogmatic methods. The significance of this thesis is not merely limited to giving us a better understanding of Sextus’ treatment of logic. If successful, this
Free Logic is an important field of philosophical logic. It appeared first in the 1950s, and Karel Lambert was one of its founders and coined the term. The volume begins with three of Lambert’s most recent essays. These papers are followed by a dialogue between Karel Lambert and Edgar Morscher on free logic. The second part of the volume contains papers by Peter Simons and Edgar Morscher on free logic. A systematic and historical survey of free logic with an annotated bibliography of works on free logic completes the book.
This book examines philosophical approaches to linguistic vagueness, a puzzling feature of natural language that gives rise to the ancient Sorites Paradox and challenges classical logic and semantics.
The Sorites, or Paradox of the Heap, consists in three claims: (1) One grain of sand does not make a heap. (2) One billion grains of sand do make a heap. (3) For any two amounts of sand differing by at most one grain: either both are heaps of sand, or neither one is. The third claim is rendered plausible by an initial conviction that vague predicates like ‘heap’ tolerate small changes. However, the repeated application of a tolerance principle to the second claim yields the further proposition that one grain of sand does make a heap – which contradicts claim number one. Consequently, many philosophers reject or modify tolerance principles for vague predicates.
Inga Bones reassesses prominent responses to the Sorites and defends a Wittgensteinian dissolution of the paradox. She argues that vague predicates are, indeed, tolerant and discusses how this finding relates to the paradox itself, to the notion of validity and to the concept of a borderline case.
The Liar paradox arises when we consider a sentence that says of itself that it is not true. If such self-referential sentences exist – and examples like »This sentence is not true« certainly suggest this –, then our logic and standard notion of truth allow to infer a contradiction: The Liar sentence is true and not true. What has gone wrong? Must we revise our notion of truth and our logic? Or can we dispel the common conviction that there are such self-referential sentences? The present study explores the second path. After comparing the Liar reasoning in formal and informal logic and showing that there are no Gödelian Liar sentences, the study moves on from the semantics of self-reference to the metaphysics of expressions and proposes a novel solution to the Liar paradox: Meaningful expressions are distinct from their syntactic bases and exist only relative to contexts. Detailed semantico-metaphysical arguments show that in this dynamic setting, an object can be referred to only after it has started to exist. Hence the circular reference needed in the Liar paradox cannot occur, after all. As this solution is contextualist, it evades the expressibility problems of other proposals.
The article examines Aristotle’s seminal discussion of the fallacy of begging the question (petitio principii), reconstructing its complex articulation within a variety of different, but related, contexts (the “dialectic” of the Topics and the Sophistical Refutations, the “logic” of the Aristotelian theory of syllogism, and the “epistemology” of the inquiry into “scientific” syllogisms). I suggest that close analysis of Aristotle’s understanding of the fallacy should prompt critical reconsideration of the scope and articulation of the fallacy in modern discussions and usages, suggesting how begging the question should be distinguished from a number of only partially related argumentative faults.
In mediaeval logic a common term is often said to supposit simply, if it supposits for a concept and not for the elements of its extension. Due consideration of the logical texts of the 13th century, however, gives rise to the assumption, that a) the common aspect of the several uses of a term which are referred to as simple suppositions is not so easy to be found and that b) for some authors simple supposition was an extensively used tool for the logical analysis of sentences. In my paper I will enlarge on this second aspect with particular reference to the syncategoremata of William of Sherwood. My study leads to the conclusion that simple supposition in the 13th century is sometimes used to analyse scope ambiguities between the existential quantor and another operator. This is due to the fact that mediaeval logicians did not conceive of anything equalling an existential quantor.