Timothy Williamson
The boundary between old evidence and new evidence depends on how the content of evidence should be individuated. The paper explores conflicting pressures on the standard of individuation. Computational considerations and Frege cases of unknown co-reference both favour fine-grained individuation. The mathematical structure of probability theory, intensional and direct reference semantics, differences in format between verbal and perceptual evidence, the need for evidence to be transmitted from one context to another in memory and testimony, and the publicity of legal evidence all favour coarsegrained individuation. The paper argues that coarse-grained individuation is theoretically better motivated, and that pressures towards fine-grained in-dividuation can be understood as resulting from our reliance on efficient but fallible disquotational heuristics for the ascription of agents’ relations to propositions on the basis of their interactions with sentences expressing those propositions. Coarse-grained models can still be adapted ad hoc to understand more fine-grained phenomena.