Writing

"The greatest invention of all must surely be writing. It is not just one of the foundations of civilisation: it underpins the steady accumulation of intellectual achievement. By capturing ideas in physical form, it allows them to travel across space and time without distortion, and thus slip the bonds of human memory and oral transmission, not to mention the whims of tyrants and the vicissitudes of history."

The writing system, and, by extension, reading, allows us to "situate [our] ideas in relation to those of previous thinkers, to argue about them and elaborate upon them. Each generation [can] build on the ideas of its forebears, making it possible for there to be species-wide progress in philosophy, commerce, science and literature."

(Source: "Writing is the Greatest Invention", Intelligent Life magazine.)