The art of deceit and self-deception, according to Plato one has to discover the true nature of the self. Art can show you how, by the encouragement to think the same way, a world that less attuned minds cannot see. Dismiss the normal vision as untrustworthy, have faith in the imagination and accept deceit and self-deception.
We can understand more about art by the understanding of human behaviour. The artist deceives by the inclusion into a work something that does not exist, and viewer imagines the object portrays something that by their self-deception they want to believe in. There may well be serious consequences outside of the arts, for art it is the essential component, the artist and viewer playing with their own self-deception. If imagination is truthful, then art itself is the deception.
“I’d rather have questions I can’t answer than answers I can’t question” - Max Tegmark