Centered worlds and the content of perception: Short version
Abstract
0. Relativistic Content In standard semantics, propositional content, whether it be the content of utterances or mental states, has a truth-value relative only to a possible world. For example, the content of my utterance of ‘Jim is sitting now’ is true just in case Jim is sitting at the time of utterance in the actual world, and the content of my belief that Alice will give a talk tomorrow is true just in case Alice will give a talk on the day following the occurrence of my belief state in the actual world. Let us call propositional content which has a truth-value relative only to a possible world ‘non-relativistic content’. Non-relativistic content can be treated as either structured or unstructured. On the unstructured-content view, non-relativistic content is a set of possible worlds and bears the truth-value true just in case the actual world is a member of that set. For example, the content of my utterance of ‘Jim is working now’ at time t is the set of worlds in which Jim is working at t, and this content is true just in case the actual world is among those worlds. On the structured-content view, non-relativistic content is a set or conglomeration of properties and/or objects, where properties are features which objects possess regardless of who considers or observes them and regardless of when they are being considered or observed. Such properties are said to be (or represent) functions from possible worlds to extensions. Relative to a possible world they determine a set of objects instantiating the property. For example, relative to the actual world the property of being human determines the set of actual humans. Not all content is non-relativistic. Let us say that propositional content is relativistic just in case it possesses a truth-value only relative to a centered world. A centered world is a possible world in which an individual and a time are marked, where the marked individual..