Full Non-Indexical Conditioning
A Bayesian framework for anthropic reasoning proposed by Radford M. Neal in a 2006 arXiv preprint (math/0608592): condition on the "global existence" of a given set of evidence or memories — that it exists somewhere in the universe — without any further indexical claim about which observer has it. Brewer, Lewis & Goodman (2026) argue FNC applied alone can license inappropriately presumptuous conclusions (echoing Bostrom's Presumptuous Philosopher problem) and develop Full Indexical Conditioning as a repair that keeps Neal's "condition on all evidence" premise while adding an indexical selection term.
- 2026-10-20 propagation-repair (scheduled cross-model audit, claude-opus-5): the superseded wording said Brewer, Lewis & Goodman "propose" FIC. The same 2006 preprint that introduced FNC also named Full Indexical Conditioning and argued against it — Neal's ground for preferring FNC is that FIC requires unique per-observer "essences" he regards as mystical. The 2026 paper revives and formalizes the alternative FNC's own author discarded. See the corrected claim-note.
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