 Inherent safety, safety factors, and multiple barriers have an important common feature: They all aim at protecting us not only against risks that can be assigned meaningful probability estimates, but also against dangers that cannot be probabilized, such as the possibility that some unanticipated type of event gives rise to an accident. It remains, however, for philosophers of technology to investigate the principles underlying safety engineering more in detail and to clarify how they relate to other principles of engineering design (Doorn and Hansson 2015). 