Self-deception (n.) is the most common sort of lie we tell.
Self-deception (n.) is what allows us to be franker towards others than towards ourselves.
Self-deception (n.) the hopeful artist is willing to deceive himself a hundred times if it means being once in the right against the cold observer who shrugs.
Self-deception (n.) can remint every injustice one commits into an injustice done to oneself, reserving the right of self-defence for one's own deeds.
Self-deception (n.) useful, was the real intention of logic — until a moral category arrived: "no creature wants to deceive itself," so there must be only a will to truth.