The Codex Arundel is a set of pages that include notes and drawings of Leonardo Da Vinci. These pages that he left behind were very helpful to us now since it was written down. This helped historians analyze and have a position on exactly what he was thinking. The writing in the pages was all detailed so it was a great primary source. Leonardo communicated all his ideas and inventions to us through his writing. This also helped us now create models of these inventions and see if they work. This was kind of a way of saying we are talking to Leonardo Da Vinci or reading through his mind.......