Alessandro Giordani is professor of logic and philosophy of science at the Catholic University of Milan, Italy, and visiting professor with the Institute of Philosophical Studies, Lugano, Switzerland, where he teaches courses in logic and epistemology. He received his PhD in Philosophy at the at the Catholic University of Milan. His research topics include modal logic, epistemic logic, epistemic justification, and models in science and measurement. Jacek Malinowski is professor of logic and philosophy at the Instituite of Philosophy and Sociology, Polish Academy of Sciences, Warsaw, Poland. He received a Master degree in Mathamatic from the University of Lódź, Poland, and PhD and habilitation in Philosophy at Institute of Philosophy and Sociology, Polish Academy of Sciences. He held research positions at Free Univeristy of Brussels, Humboltd University in Berlin, University of Leipzig, the Netherland Institute of Advanced Study in Wasenaar. He publish papers in algebraic logics, quantuum logics, logical pragmatics. He is active as editor-in-chief of Studia Logica what he consider his main professional concern.