The ontology of justifications in the logical setting

Justification Logic provides an axiomatic description of justifica-tions and delegates the question of their nature to semantics. In this note, we address the conceptual issue of the logical type of justifica-tions: we argue that justifications in the logical setting are naturally interpreted as sets of formulas which leads to a class of epistemic mod-els that we call modular models. We show that Fitting models for Jus-tification Logic naturally encode modular models and can be regarded as convenient pre-models of the former.