What impact did written language have on communication?

Written language forever changed communication in numerous ways.

The visual medium of written language itself allowed for information to be stored in an accurate manner. No longer were pictures drawn that were open to interpretation. Actual history could be documented and preserved for future historians to read, comprehend, and learn from.

The ability to recall information that was written assisted even oral communication. Imagine giving a long speech that you could not practice consistently every time. Imagine attempting to work out an algebraic equation without showing the steps to get to the end. Imagine trying to sit in class and absorb knowledge that would later need to be reviewed for a test without notes. Not only is it about storing the information, but being able to recall the information to assist with cognitive thought.

Written language lead to the creation of the clock and keeping time. France used this in the 1300's to revolutionize the common work schedule still seen today in many industries.

Written communication meant that letters could be sent to anybody without the loss of information in oral interpretation or translation. An accurate message could be sent long distances for the first time! This is actually a very exciting thought. Imagine people conveying information they are trying to remember without any written documents; no telling how many misinterpreted messages lead to problems.

Written language has altered the way human thinks. Logic can be applied now. Science can be studied and documented. Philosophy can be written and passed. All aspects of life changed with the creation of the written language. 

I think we owe a big thanks to the Greeks. We also have to consider the other influences, especially Hindu mathematicians that gave us the number 0!