No one can know how another person will act in the future.

Evidence

No one can know how another human being will act in the future. Trust is a policy apt for conditions where knowledge is unavailable, as in the case of the free acts of another person (in Locke’s view) it will always remain. — Diego Gambetta, Trust - Making and Breaking Cooperative…, 1197

Categorization

• XREF: Causal chain: unobservable future acts of free agents → knowledge unavailable → trust as the only proper policy. Mirrors how blindness removes observability in Saramago.