Overview of the endogenous and exogenous approaches to the semantics of probabilistic logic. Language, semantics and deductive system of EPPL (Exogenous Probabilistic Propositional Logic). Evaluation of what can be expressed in EPPL. Outline of the proof of completeness. Brief reference to future developments of the proposed technique for probabilizing logics. The talk is a follow up of the presentation by A. Sernadas at the Portuguese Category Seminar 2003 in Coimbra and reports ongoing joint work with A. Sernadas, C. Sernadas and A. Pacheco.