Third is a book written by Bertrand Russell and Whitehead together. Nobody reads it. The title is Principia Mathematica. Just the name is enough to make people afraid, and the book must be the most difficult in existence. Hence, I worked on that book as much as possible. Anything difficult always allures me. The book is enchanting and challenging, but I will not recommend it to my sannyasins. Avoid it! I went through those thousands of pages and found nothing but mathematics. Unless you are interested in mathematics, particularly higher mathematics...that is another matter. I wanted to include it because it is a masterpiece – of mathematics.