" The deadly arrows do not strike the hero from without; it is himself who hunts, fights, and tortures himself. In him, instinct wars with instinct; therefore the poet says, “Thyself pierced through,” which means that he is wounded by his own arrow. As we know that the arrow is a libido-symbol, the meaning of this “piercing” is clear: it is the act of union with oneself, a sort of self-fertilization, and also a self-violation, a self-murder, so that Zarathustra can justly call himself his own hangman (like Odin, who sacrifices himself to Odin). One should not of course take this psychologem in too voluntaristic a sense: nobody deliberately inflicts such tortures on himself, they just happen to him. If a man reckons the unconscious as part of his personality, then one must admit that he is in fact raging against himself. But, in so far as the symbolism thrown up by his suffering is archetypal and collective, it can be taken as a sign that he is no longer suffering from himself, but rather from the spirit of the age. He is suffering from an objective, impersonal cause, from his collective unconscious which he has in common with all men. "
― C.G. Jung , Symbols of Transformation (Collected Works 5)