Art can most definitely bring to light Knowledge and Truth of Self foremost,
and in'sight into almost any other topic of life besides.
(particularly relational truths)
Note: Subjective truths are truths in relation to the Subject "I've".
EDIT: and "gnosis" is sudden knowing.
(even before any logical reasoning is applied)
"Truth of self" is sort of ambiguous, but as far as I can guess it either means our aesthetic perceptions (which is not knowledge, but qualia) or analyzing ourselves for how we interpret the piece in question (which sounds like rational inquiry to me).
As for gnosis being "sudden knowing," before reasoning is applied, is this the same concept as a priori reasoning?