This special issue of “Axiomathes” is devoted to a technique originally developed within library science: facet analysis. During discussions with Roberto Poli, it was realized that facet analysis shares interesting features with analytical methods in several other fields, including philosophy, psychology, linguistics, and computer science. For these reasons, in an interdisciplinary spirit, we believe that facet analysis is a relevant topic for the scope of this journal. It is hoped that readers will be persuaded by this after examining the present contributions.