Unknowability
In philosophy, unknowability is the possibility of inherently unaccessible knowledge. It addresses the epistemology of that which we cannot know. Some related concepts include the halting problem, the limits of knowledge, the unknown unknowns, and chaos theory. Nicholas Rescher provides the most recent focused scholarship for this area in Unknowability: An Inquiry into the Limits of Knowledge, where he offered three high level categories, logical unknowability, conceptual unknowability, and in-principle unknowability.