ABSTRACT

Introduction I hope that my contribution to this volume will be read as an essay (literally “a try, an attempt”), a literary genre defined as the presentation of general material from a personal, not balanced, point of view; my contribution should not be read as an academic or technical piece of writing, well balanced and well referenced. Instead please consider this as an attempt to clarify, mostly for my self, some general ideas and observations about unexampled events, resilience, and Probabilistic Risk Assessment (PRA).