Here I share some pieces of the current draft version of one of my articles on opacity in natural languages. I shall post one excerpt or two by day. Hope you like it. Comments are wellcome.
ON OPACITY
1. Prelude
1.1 General Considerations
A. The Issue
In this work I shall examine some aspects of the semantic phenomenon called opacity from the perspective of human languages in their common usage (rather than artificial languages or usages created by Logicians), relating it to the manner such languages, as computational systems, equip their users with the tools and the techniques to handle (pseudo-) paradoxes and explosions caused by contradictions. Although I resort to the work of Logicians and Philosophers, the principles and theoretic notions herein proposed to formalise such phenomena are primarily hypotheses respecting the inherent machinery of human languages, rather than merely invented solutions to approach the issues in question.
The latu sensu notion of opacity can be initially figuratively characterised as the phenomenon of a sentential context not allowing the light of a semantic/logic principle to pass through, i.e., a certain context is opaque because a certain (mode of) inference is not visibly valid therein.
There have been some more specific and/or stronger hypotheses trying to define actual instantiations of this notion occur and/or to predict when and to explain why they occur. Indeed, as far as I know, there have been at least two basic approaches on opacity.
The first basic approach on opacity, which is herein called classic or traditional, and which will be questioned in Section 2, assumes the definition of opaque context given in (1) below or variants thereof: Although (1) has never been accepted by important academic factions, like the Russellian philosophers among others, it is still the most spread conception in the literature:(1) Opaque context (classic version)
A sentential context C containing an occurrence of a term t is opaque, if the substitution of co-referential terms is an invalid mode of inference with respect to this occurrence. (See Mckinsey 1998, Quine 1956)
The second basic view, which will be approached in Section 4, revolves around the idea of non-symmetry of accessibility relations. This second view has more adepts among linguists.
The alternative view I shall sketch here attempts to determine how fundamental opacity is and to relate it to issues of consistency and non-paradoxical interpretation in the common usage of natural languages.
