The Responsible Phantasm

"The terms 'fantasy' and imagination originate in Greek and Latin, respectively. [...] 'Fantasy', the Latinized version of the Greek, has acquired a steam of distinct associations with the result that shades of difference now operate to distinguish imagination from fantasy in common usage, in ways that effloresce from definitions attempted by Renaissance philosophers. Pietro Pomponazzi (d. 1525) restricted fantasy to the sleeping mind alone, and granted imagination a connection with conscious perception. Imagination still caries these more positive, rational, even civic overtones: in common parlance, 'Use your imagination' does not mean 'Go ahead, fantasize', but rather evokes conscious, responsible, and sympathetic behaviour, by contrast with 'You're fantasizing', which calls to inner realms of the unconscious and dream."

- Marina Warner, Phantasmagoria