Some Problems with the Thin Red Line

Jacek Wawer (Jagiellonian University)

In the branching model, temporal possibilities are represented in shape of a tree-like structure. We argued (in Malpass and Wawer 2012) that it is reasonable to enrich the branching model with an additional factor which distinguishes a single branch--the Thin Red Line--as the unique scenario that is actualized with the passage of time. The Thin Red Line (TRL) theories face a traditional challenge repeatedly stated by Nuel Belnap. Namely, TRL is useless for interpretation of predictions made outside of TRL (non-actual predictions). To answer the problem, we devised a new semantic theory: Supervaluational Thin Red Line. Andrea Iacona (2014) argued that our proposal generates severe semantic failure. He asserts that according to our theory, the meaning of linguistic operators (such as disjunction, future tense, or actuality operator) differs depending on whether they are interpreted in actual or non-actual circumstances. We claim that there is a more charitable interpretation of our theory which preserves the meaning of linguistic expressions across the model. Under this interpretation, our proposal is seen as postsemantic, rather than semantic theory (in the sense of MacFarlane 2014). Iacona's paper provoked us, nonetheless, to critically reassess our original project and the role of the Thin Red Line in the semantics of branching. We notice that the clumsy, disjunctive feature of our proposal is not accidental, but it's enforced by the content Belnap's challenge. After all, he explicitly calls for procedure to interpret sentences used in non-actual circumstances. We think now that the best way to react to Belnap's worry is to insist that all predictions are actual predictions in which case his challenge doesn't get off the ground. We sketch two ways to explicate the slogan--elitist and egalitarian--which allow for bivalent treatment of future contingents, free from Belnap's worry.