We use written symbols to express all kinds of messages: to share stories, note financial transactions, record history, imagine the future, to express love, hatred, humour or melancholy. Writing gives us access to knowledge. We can trace how an idea has changed over thousands of years, or argue against the opinions of those long dead, all because the discoveries of others have been recorded and collected.
According to historians, the earliest form of writing can be dated to around 3000 BC, when Sumerians in ancient Mesopotamia - modern day Iraq - wrote on clay tablets. This writing system is known as cuneiform.
Are there alternatives to writing?
Some of the most basic forms of communication use simple devices, often in moment to moment exchanges. A Yoruban man in Nigeria might send six shells to the woman he is attracted to. The Yoruban word efa means both 'six' and 'attracted'. If this chat up line works, the girl replies with eight shells - ejo meaning both 'eight' and 'I agree'.
The Iron Age Celts didn't write things down but passed on their knowledge, stories and poems by word of mouth. It took their druids up to twenty years to remember everything. They were a highly sophisticated society, and knew about writing, but preferred to learn everything by heart.
Transmitting a story from person to person is a fluid process - much more so than reading a text fixed on a page. In the process of hearing a story, and retelling it, subtle changes can chip away at the story itself. Our different experiences and interpretations can influence the meaning of the story, and affect how we choose to pass it on.
By contrast, writing is an act of recording. The word written becomes fixed. Depending on what it is written with, its mark can remain preserved for a very long time. Although different readers might interpret a piece of writing in different ways, the text itself does not change.
Of course, since the late 1800s advances in technology have had a profound effect on our society's dependence on writing. Recording equipment has allowed us to record our stories, fixing them in time for as long as the physical record lasts, while telephones have allowed us to speak to people on the other side of the world.