在《理想国》中,柏拉图讲过一则洞穴寓言:一些人被囚禁在一个洞穴里,他们的头脚动弹不得,只能终日面对洞穴的后壁。他们的身后有亮光从通道照射过来,将外面世界各种物体的影像投射到洞壁上。囚徒们谈论着这些影像,认为这就是实物本身。直到有一个人走出洞穴,眼睛逐渐适应了太阳 In “The Dreamland,” Plato told a cave allegory: Some were imprisoned in a cave, their head and feet could not move, only the face of the caves all day long. Behind them was the light shining through the passage, projecting images of various objects from the outside to the walls of the cave. Prisoners talk about these images, that this is the kind of object itself. Until a person out of the cave, the eyes gradually adapted to the sun