“Suppose someone told of a thing of a certain kind, and of certain things that had happened to it; and, when asked where that thing had been, and when the events he recounted had occurred, said, not that he did not know, but that they did not belong at all to our spatio-temporal system, that they did not take place at any distance from here or at any distance of time from now. Then we should say, and take him to be saying, that the events in question had not really occurred, that the thing in question did not really exist” (Strawson, Individuals, 29).
This passage raises questions about what it is we understand when we understand fiction. We follow a story, we understand that something happened, and at what location in the world of the story it happened; but the relationship between that world and the actual physical world may be loose. Perhaps so long as we have a time and place, whatever their relation to the actual world is, that fulfills Strawson's criterion. Perhaps what we do in entertaining fiction is akin to building on a temporary annex to our idea of the universe.
I suspect we do something similar in other contexts. In fact, I think a similar move is indispensable to our cognitive lives in societies.
Closed systems are abundant in philosophy. Carnap's sciences form their own systems, built upon axioms that are not themselves subject to the kind of examination they make possible; the cultures of cultural relativism are closed systems--each with its own ways of defining or cashing out normative terms; our conceptual scheme, for Strawson, seems to form such a system, insofar as he thinks skeptics are incapable of questioning it without also relying on it in so doing. Any argument that a position is self-undermining indicates that the self-undermining position's proponent is trying to break out of a closed system and failing.
In the cultural relativism case, in which 'right' is defined only for individual societies, there is no way of saying that anything is trans-culturally right or wrong. This, Bernard Williams argues, shows that cultural relativism is incoherent, as 'right' is used in a trans-cultural way in arguing to the conclusion that, since 'right' is only defined for individual cultures, it is wrong to interfere with another culture's actions expressing their values.
The response I'm inclined to give here is that there must be a way of arriving at an overarching definition of 'right' (which, of course, undermines relativism). And surely this is what we do when we talk to each other; we might cause someone else, or be caused, to revise our own values. That there is a trans-cultural way of understanding moral concepts is presupposed by the fact that we can talk to people with different values. Those trans-cultural understandings might be acts of the imagination, applied to our own concepts (and to human experience), looking for some way of bridging the gap. We might be noncommittal about the objective definitions of normative terms, but hold working theories. To do this is to leave the system of values, based upon a definitions of normative terms, open--open to revision of those definitions upon 'evidence' supplied by conversations and other evidence provided by witnessing, say, the effects of values, policies, or laws.
I doubt that such acts of the imagination provide an escape from skepticism. About that, I believe Strawson is correct. I concede, for example, that the skeptic about other minds presupposes their existence in imagining his or her own experiences as missing for other people. This is not to say there's nothing it is to imagine that others do not have experiences: we can imagine this. But if one tries to put together a coherent world around the conceit, it either ceases to exemplify the philosophical problem of other minds, or falls apart, turning in on itself like Castrovalva.
Certain regions of our concepts are, as it were, on the front-lines receiving assaults from experience, normative concepts and spatio-temporal locations for stories heard first among them.