A philosopher argued that nothing exists unless something is perceiving it

George Berkeley argued that physical objects don't exist independently of minds, they're really just bundles of qualities we perceive, like color and texture. His slogan, 'esse est percipi,' means 'to be is to be perceived.' Since objects seem to persist even when no human is looking at them, Berkeley argued an ever-present mind, God, must be perceiving everything at all times to keep the universe in existence.

— George Berkeley, A Treatise Concerning the Principles of Human Knowledge — 1710