For that fish, the glass walls define reality. It does not know the idea of “outside,” because everything it has ever experienced happens within. The reflections on the glass are its horizon. Now, place two aquariums side by side. The fish see each other and believe they share one world. They are mistaken - yet their mistake is understandable, because illusion always feels real when the glass is clear enough. We humans live in similar aquariums.Our tanks are made of concepts, languages, belie...