What was the significance of the text being written by a member of the first estate?

Emmanuel Joseph Sieyès - Wikipedia, the free encyclopedia (http://en.wikipedia.org/wiki/Abbe_Sieyes)

Being of the 1st estate he was able to garner some support from clergy and some nobles.He was a moderating voice in an otherwise extreme revolution. Eventually he was instrumental in Napolean's rise to power. When the Bourbon's regained power he was exiled.