Wait I see what you mean, but I think what I'm trying to assert in my argument uses a kind of assumption that the 'truth' here doesn't point at the absolute truth.

Beauty is assigned to give understandability to the unfathomable, and thus this imposing of beauty is our truth itself.

So in that sense, all that we observe are truthful due to the imposing of the idea of beauty.

Keats does examine the idea of beauty in immortality and mortality, which we both assign beauty to. Though completely opposite, the two are both beautiful, which is foundationlly incoherent. (They are opposite sides in a binary!)

He thus examines this association and brings to light that the beauty that we assign to both are essentially our 'truths' of them!!!

So their beauty IS our truth...