Circumstantialists already have a logical semantics for impossibilities. They expand their logical space of possible worlds by adding impossible worlds. These are impossible circumstances serving as indices of evaluation, at which impossibilities are true. A variant of circumstantialism, namely modal Meinongianism (noneism), adds impossible objects as well. These are so-called incomplete objects that are necessarily non-existent. The opposite of circumstantialism, namely structuralism, has some catching-up to do. What might a structuralist logical semantics for impossibilities without impossibilia look like? This paper (...) makes a structuralist counterproposal. We present a semantics based on a procedural interpretation of the typed λ-calculus. The fundamental idea is that talk about impossibilities should be construed in terms of procedures: some yield as their product a condition that could not possibly have a satisfier, while the rest fail to yield a product altogether. Dispensing with a ‘bottom’ of impossibilia requires instead a ‘top’ consisting of structured hyperintensions, intensions, intensions defining other intensions, a typed universe, and dual (de dicto and de re) predication. We explain how the theory works by going through several examples. (shrink)

The book is about logical analysis of natural language. Since we humans communicate by means of natural language, we need a tool that helps us to understand in a precise manner how the logical and formal mechanisms of natural language work. Moreover, in the age of computers, we need to communicate both with and through computers as well. Transparent Intensional Logic is a tool that is helpful in making our communication and reasoning smooth and precise. It deals with all kinds (...) of linguistic context in a fully compositional and anti-contextual way. (shrink)

Theoretical representations in discussions surrounding the semantic significance of words and their analogs in thought should not be viewed under a realist interpretation as individually revealing what the represented items really are. Instead, they should be viewed under an instrumentalist interpretation as having other roles to play within their respective explanatory contexts. I consider some case studies for this broad methodological claim: theoretical representations of the semantic significance of words within semantics, theoretical representations of what determines the semantic significance of (...) words within metasemantics – both under the auspices of the so-called new theory of reference – and theoretical representations of cognitive attitudes within the Representational Theory of Mind. (shrink)

In a 1997 paper Jennifer Saul adduces various examples of simple sentences in which the substitution of one co-referential singular term for another appears to be invalid. I address the question of whether anti-substitution is logically justified by examining the validity and soundness of substitution of co-referential singular terms in three simple-sentence arguments each exhibiting a different logical structure. The result is twofold. First, all three arguments are valid, provided Leibniz’s Law is valid with respect to simple sentences . Thus, (...) as far as these arguments are concerned, there is no logical problem with substitution in simple sentences. Second, two of the arguments cannot be sound, because their respective sets of premises are inconsistent. Thus, it would be logically irrational to commit oneself to all the premises of the respective arguments. To the extent that the origin of Saul’s puzzles is in logic , I suggest, tentatively, that substitution may appear to be invalid because the issues of validity and soundness have not been kept separate. I then consider in depth Saul’s first sentence, “Clark Kent enters a phone booth and Superman exits”. Obviously, two-way substitution is trivially valid, if the expressions are co-referential semantically proper names, the conclusion being but a rephrasing of the premise. However, I argue that a non-trivial semantic analysis of this sentence should take account of the diachronicity of Clark Kent’s entrance and Superman’s exit while preserving the internal link between being Superman and being Clark Kent. I propose the following. ‘Superman’ and ‘Clark Kent’ refer to two distinct individual concepts. “Superman is Clark Kent” then no longer expresses the self-identity of an individual bearing two names, but that two named concepts are held together by the requisite relation: wherever and whenever someone falls under the concept of Superman the same individual also falls under the Clark Kent concept, whereas there are exceptions to the converse. This semantic analysis always validates the substitution of ‘Clark Kent’ for ‘Superman’, but validates the substitution of ‘Superman’ for ‘Clark Kent’ only if the additional condition is met that somebody should fall under the Superman concept when Clark Kent. (shrink)

We tend to think that our concepts are stable in the sense that, whilst their extensions may vary across distinct epistemic scenarios, the reference-fixing conditions by which we discover these extensions remain fixed. This paper challenges this orthodoxy. In particular, it aims to motivate the position that some concepts are unstable in that their reference-fixing conditions themselves vary across distinct epistemic scenarios. Furthermore, it aims to draw out the implications such instability has for epistemic possibility and apriority. I shall argue (...) that when unstable concepts are concerned epistemic space will be widened, which in turn will restrict our a priori knowledge; and in ways that might be salient to solving certain familiar philosophical problems. (shrink)