Towards a concept of uncertainty

Uncertainty is a crucial concept in our life, and consequently it is pervasive in both the sciences and philosophy. And yet, while there are several frameworks to identify different types of uncertainty, to design instruments to represent them more or less quantitatively, and to explore their implications for scientific practice and for decision-making, there are almost no general accounts of what the concept of uncertainty in itself is. This work proposes three requirements that a philosophically sound concept of uncertainty should satisfy. First, it should allow for variability, i.e. for the possibility that there are different types of uncertainty with which uncertainty should be in a genus/species relation. Second, it should be agent-dependent, and therefore possibly change with the agent or with their situation. Third, it should include gradable elements that allow to account for the fact that uncertainty comes in degrees, and that sometimes it can be reduced. These are necessary requirements for a philosophical analysis of uncertainty to be acceptable, but they are neither sufficient nor exhaustive. I conclude by illustrating how these requirements play out with respect to three alternative possible definitions of uncertainty.