In the oasis complex, the thirsty man images he sees water, palm trees, and shade not because he has evidence for the belief, but because he has a need for it. Desperate needs bring about a hallucination of their solution: thirst hallucinates water, the need for love hallucinates a prince or princess. The oasis complex is never a complete delusion: the man in the desert does see something on the horizon. It is just that the palms have withered, the well is dry, and the place is infected with locusts.