I argue that evaluative uncertainty gives rational agents instrumental reasons to abstract from some of their salient preferences when bargaining about social institutions. Because agents cannot assume stability in their future evaluative outlook, it is rational to favour rules that preserve options that may become salient. Building on Kreps (1979), I show how flexibility-driven abstraction expands the bargaining set, enabling convergence on rules while preserving motivational continuity. Since options are endogenous, bargainers also have reason to deliberate about option-generating and option-filtering meta-rules that structure the emergence, appraisal and revision of options over time.
