an experiment in which flies were sealed in an aerated jar and left for an extended period of time. Finally the lid on the jar was removed, but—strange thing—the flies did not try to leave. Well conditioned by now, they no longer looked for the exit. They just kept circling the tight perimeters of the glass, going in their familiar patterns. Their reality had shrunk to that jar. It had become their entire world. It had become safe. Life beyond it had ceased to exist.
