The idea that we could invent tools that change our cognitive abilities might sound outlandish, but it’s actually a defining feature of human evolution. When our ancestors developed language, it altered not only how they could communicate but how they could think. Mathematics, the printing press, and science further extended the reach of the human mind, and by the 20th century, tools such as telephones, calculators, and Encyclopedia Britannica gave people easy access to more knowledge about the world than they could absorb in a lifetime.
