I don’t think we need an additional concept. I believe the key is that, as you point out, “truth” is an epistemological concept in that it is always based on the context of all that is known at the time. At one time, all known facts supported that all type A blood was compatible with other type A blood and thus it was true in the context of those facts.Later, based on the discovery of additional facts, the truth had to be qualified as you stated.All true statements must be understood as being qualified by “based on what we know at this time” since, as Peikoff noted, all truth is contextual. To demand that some truths be without such a context is to require a base of omniscience which is an impossibility.In the Ayn Rand Lexicon “truth” is defined as “the recognition of reality” meaning it is a relationship between a human mind and reality.
