H. Walter Schmitz: Introduction / I. SIGNIFICS AS A STARTING POINT OF RESEARCH: Christian Thiel: Brouwer’s Philosophical Language Research and the Concept of the Ortho-Language in German Constructivism / Dirk van Dalen: Brouwer’s Dogma of Languageless Mathematics and its Role in his Writing / Erik Heijerman: The Validity of Mathematics as a Pseudo-Problem / Gerard Alberts: Signific Consultation. David van Dantzig’s Dream of a Practical Significs -- II. ON THE HISTORY OF SIGNIFICS: Klasien Horstman: Victoria Welby, a Moralistic Pragmatist! / L.J.M. Bergmans: Otto Friedrich Gruppe as a Precursor of the Significians -- III. SIGNIFICS COMPARED: Achim Eschbach: Charles W. Morris and Gerrit Mannoury. A Juxtaposition / Norman M. Martin: Significs and Logical Empiricism / Henk Visser: Significs in Linguistic Philosophy -- IV. ON THE TOPICALITY OF SCIENTIFIC METHODS FOR ANALYSIS: H. Walter Schmitz: Empirical Methods of Signific Analysis of Meaning. Transformation and Exhaustion of Linguistic Acts / Adriaan D. de Groot: Signific Concept Analysis / Fester L. Medendorp: Rethinking Signific Issues / Erik Heijerman: Summary of the Final Discussion / Index of Names