Explanation: Written laws are important for several reasons. Written laws provide a shared reference. Once a law is written down, there is an objective record of what the law is. That means if you can read the law, or can get someone to read the law to you, you can use it.On the most basic level, you can consult it directly, so you know what to do and not do.
Laws existed before writing, but they were held in memory. This meant you had to go to the people who knew the law (usually the wise elders of a society) and ask them what the law was. This means the oral transmission of culture is disrupted, these laws can mutate or be lost.
Written law also allowed a society to grow beyond a certain size. To use the example from above, in an oral culture you either have to be directly in the presence of the people who know the law, or have the law passed on to you by word of mouth. That puts a practical limit on the size of a society. Written laws allows continuity across space. Imagine trying to govern a nation like the United States using only laws passed on through word of mouth. That would be next to impossible.
Historically, writing laws down allowed a kind of democratization of power. You can see this in ancient Rome, when the common or plebeian class pushed for a change from an oral legal tradition, and for laws to be written down.
