The endogeneity requirement

The endogeneity requirement is the clause of the Tracking Minimum that requires a source’s connection to the truth to hold in virtue of its own production process, rather than in virtue of a proxy on which that process depends. It is, I argue, what the leading accounts of testimony share and what current language models fail.

Without it, a merely statistical condition returns by the back door, because explanation is promiscuous. Evidential support explains what gets attested in a corpus; attestation explains what a corpus-trained process emits; so evidential support figures, at some remove, in the explanation of every output. Endogeneity rules this out. Where a process is connected to the truth only because it is connected to a proxy that is itself so connected, the proxy screens the truth off: hold the proxy fixed and vary the truth, and the output does not move.

Lackey’s creationist teacher shows what meeting the requirement looks like without belief (see selfless assertion). Introduce into her textbook an error of a kind her competence can detect, and she flags it rather than teaching it. Vary the evidence within the reach of what she can assess, and her assertions follow. The textbook does not screen the evidence off, because her competence can be brought to bear against it.

The requirement also explains how a process reliabilist can be held to the same condition. Reliability is always reliability of a type, and a type can be drawn narrowly enough to make almost anything reliable. Goldberg draws the line where the requirement does: the reliability that constitutes a hearer’s warrant must belong to the operation of an epistemic subject, not to a fortunate alignment between a mechanism’s outputs and the world.

For a language model, the production type it most naturally instantiates is emitting the continuation with high likelihood given the prompt. That type is truth-conducive when, and because, the conditions of use resemble those under which its corpus regularities are truth-indicative. Its connection to the truth is real, and exogenous. Whether something else governs production is an empirical question, and the requirement says what would settle it.