Tink was not all bad: or, rather, she was all bad just now, but, on the other hand, sometimes she was all good. Fairies have to be one thing or the other, because being so small they unfortunately have room for one feeling only at a time. They are, however, allowed to change, only it must be a complete change.
James M. Barrie (2013). “Peter Pan (Peter and Wendy) (Annotated Edition)”, p.52, Jazzybee Verlag