Chapter 67: Bayesian Inference at Meso/Macro Scale

At the micro scale, logic is Boolean: a morphism exists or does not, a diagram commutes or does not . At the meso and macro scales—where multiple NF addresses are involved, where evidence is partial, and where competing hypotheses must be weighed—logic becomes Bayesian. Degrees of credence replace binary truth values, and belief revision follows from conditional probability understood as a categorical operation. This transition is not a departure from τ-logic but a structural consequence of scale: when the observer cannot resolve individual addresses, uncertainty enters not as an epistemic deficiency but as a feature of the scale at which inquiry is conducted.