Why are writing systems and paper important inventions?

The invention of writing divides time into pre-history and history. Writing has many forms and purposes, but all written material has something in common: the transmission of information. Prior to the invention of writing, all communication of information was verbal or based on body language. Writing has the benefit of being more inclusive with regards to content — speaking often demands that we leave some information out — as well as the possibility to share information throughout time and across space. The major reason we know so much more about history than pre-history is because historical time is defined by having been recorded in some form of writing. 

Writing first developed in Ancient Sumeria, but was also independently developed in Mesoamerica and China. Early written material in Sumeria was primarily for accounting and administrative purposes, while in China, writing developed out of divination practices. Regardless of where writing systems developed, people rapidly began keeping track of what was happening around them as well as sharing narrative histories and myths. 

Writing and paper to write on are fundamental parts of most people's education. It is really wonderful that information can be recorded in or on some material and preserved for others to learn. Having an intermediary form of information, like a book, changes the nature of information exchange between people. The human brain is not perfect when it comes to retention, and it is highly unlikely that any one person could remember as much as they wanted or needed to. Those early Sumerian accountants certainly wanted to keep track of all of their goods and stores, but found writing to be more efficient than trying to remember it all.

I would argue that paper is a less important invention than writing, as many materials have been used to record information. Vellum, cotton, hemp, clay, stone, wood, and even papyrus have all been used for writing surfaces. Wood-pulp paper is certainly a major industry in our world, and most texts are printed on wood-pulp paper. If wood-pulp paper had never been invented, we might just read books printed on hemp instead.

Writing is a dynamic and expressive form of information that enables the intellectual pursuits of people throughout time and across space.