Professor Tolkien on the nature of evil:
http://www.pages.drexel.edu/~std26/FOTR.pdf
http://www.wickedness.net/ejv1n3/book.pdf
There was a Fourth Conference on Evil and Human Wickedness in Prague in 2003.
The Wickedness.Net project seeks to explore all issues relating to evil and human wickedness. In particular, it has two main aims;
to provide a comprehensive forum which is committed to promoting inter-disciplinary and multi-disciplinary explorations of, and perspectives on evil and wickedness.
to make available to scholars, researchers, and any one interested a set of research tools that bring together a wide variety of materials and resources which relate to this subject.
What is "evil"?:
http://www.wickedness.net/Foreword.pdf