The extraordinary in decision-making: myth, apology or opportunity?

Robustness, resilience and anticipation are essential aspects of a system's first line of defence against exceptional hazards and high-impact unexpected events. This paper questions both the principles and the need of digging too deep into the often intangible world of high-consequence low-probability events that have the potential to impact systems and society as a whole. The engineering community has recently taken to referring to certain events as black swans, perfect storms or events caused by a priori unknowable unknowns, as if such appellation would constitute an apology for their sudden occurrence. We show that many of these metaphoric notions are either conceptually inappropriate, mostly from an epistemic point of view; or else, that they have little operational bearing on our knowledge base and on best practice rational decision-making.The case studies illustrate their conceptual and metaphorical role in a world of interconnected networks of everything.