Transparency and publicity are often used interchangeably, despite repeated calls for clearer differentiation in the growing literature on transparency. The chapter investigates whether there is a discontinuity of meaning between the principle of publicity, which appears in classical writings, and the call for transparency emerging in parallel as a metaphor in the eighteenth century. Baume discusses the reasons for distinguishing between the concepts of transparency and publicity and builds on suggestions by Tero Erkkilä, Jon Elster, Erin Kelly, and Daniel Naurin. After analyzing the contributions and limitations of these authors, she suggests a different method of distinguishing publicity from transparency by drawing on the polyvalence in the semantics of the latter.