The question of the interpretation of impossible pictures is taken up. Penrose's account is reviewed. It is argued that whereas this account makes substantial inroads into the problem, there needs to be a further ingredient. An inconsistent account using heap models is proposed.

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One of the few points of agreement to be found in mainstream responses to the logical and semantic problems generated by vagueness is the view that if any modification of classical logic and semantics is required at all then it will only be such as to admit underdetermined reference and truth-value gaps. Logics of vagueness including many valued logics, fuzzy logics, and supervaluation logics all provide responses in accord with this view. The thought that an adequate response might require the (...) recognition of cases of overdetermination and truth value gluts has few supporters. This imbalance lacks justification. As it happens, Jaskowski's paraconsistent discussive logic-a logic which admits truth value gluts-can be defended by reflecting on similarities between it and the popular supervaluationist analysis of vagueness already in the philosophical literature. A simple dualisation of supervaluation semantics results in a paraconsistent logic of vagueness based on what has been termed subvaluational semantics. (shrink)

It is commonly suggested that vagueness is a purely semantic phenomenon having no metaphysical or ontological implications, requiring no new ontological category for its explanation. It does not entail any revision of the metaphysical view that the world is precise or determinate contra advocates of a vague or fuzzy ontology like Bertil Rolf and Michael Tye. The suggestion is often bolstered by arguments that purport to show that the world is completely describable in a precise language. The precision of the (...) world is then taken to follow from the availability of such a complete precise description thereof. In this sense vague language might be considered superficial. (shrink)