Great fiction can be a source of great truths, truths which go beyond mere fact. I have just been re-reading Ursula le Guin's 'Earthsea' novels. If anyone who sees this hasn't read them yet, do! They are masterpieces in the fantasy genre.
Great truths are not necessarily new, but bear contemplating anew, particularly in the words of such a gifted writer. Here is a piece from A Wizard of Earthsea, in which her main character, Ged, integrates his shadow into himself:
'... had made himself whole: a man: who, knowing his whole true self, cannot be possessed by any power other than himself, and whose life therefore is lived for life's sake and never in the service of pain, or hatred, or the dark.'
It is the suppressed and/or unrealised parts of the self which, remaining unintegrated, can cause trouble.
First, we have to know they are there. It helps, I think, to accept that 'we all carry within us' — as my old shrink once said — 'the ape, the savage and the child.' That gives us some power to notice these aspects, reassure them if necessary, and to decide when it is appropriate to indulge them or refrain. Good wizards, good witches — indeed, good people — are those who understand what we are all capable of, who do not exempt themselves from the horrifying truth, and who choose deliberately and wisely.