Safety is an inherently inconsistent concept

Some basic principles for philosophical definition work are introduced and then applied to safety and related concepts. Definitions are provided first for comparative safety concepts such as “safer than” and then for the monadic “safe”. It is shown that “safe” is an inherently inconsistent concept, i.e. it cannot be restored to consistency without giving up what we perceive as some of its central elements. The reason for this is that both absolute and relative conceptions of safety are entrenched in common usage of the term. In order to avoid the inconsistency a strategy of terminological ramification is proposed: We should distinguish between the two concepts “reasonably safe” and “absolutely safe”. Any usage of “safe” or “safety” simpliciter should be seen as an abbreviated reference to one of these two closely related, remarkably confusable, but still unmergable concepts.

► Clarifies how philosophical decision tools can be helpful in safety science. ► Provides precise definitions of the central terms “safe”, “safety”, and “safer than”. ► Shows how “safe” is an inherently inconsistent concept. ► Proposes improved terminology that avoids the inconsistency.