What is the theme in The Silmarillion by J.R.R. Tolkien?

Pride is a common theme that runs throughout The Silmarillion and creates much of the conflict and action. It is easy to discover Melkor and Feanor as the most prideful beings in the tale, but there are many instances of lesser pride present as well. Melkor's original ambition when Iluvatar first reveals the theme along with his attempts to rule on Ea result in the dichotomy of good versus evil and leads to the many wars that occur between Melkor and the Valar, Elves and Men. Melkor covets Arda and attacks the Valar, revealing his pride in his belief that he is powerful enough to attack the Valar which are more numerous.