Since their inception, the Perspectives in Logic and Lecture Notes in Logic series have published seminal works by leading logicians. Many of the original books in the series have been unavailable for years, but they are now in print once again. This volume, the twenty-seventh publication in the Lecture Notes in Logic series, contains the proceedings of two conferences: the European Summer Meeting of the Association for Symbolic Logic and the Colloquium Logicum, held in Münster, Germany in August, 2002. This compilation of articles from some of the world's preeminent logicians spans all areas of mathematical logic, including philosophical logic and computer science logic. It contains expanded versions of a number of invited plenary talks and tutorials that will be of interest to graduate students and researchers in the field of mathematical logic.