 On such a reading, there is no substance, outside of the practical context, to the question of whether an appearance is numerically identical to a thing in itself, so the identity and non-identity versions of, e.g., phenomenalism, are  equivalent.[63]  If one holds instead that these identity claims have a content but that we cannot know them on theoretical grounds alone (see section 5.1) then one will likewise see these interpretive options as so constrained, because, although there is a difference in content between, say, the identity and non-identity versions of phenomenalism, Kant must be agnostic as to which is true.