I will admit that I had lived for over 30 years before I heard about William James. He was a psychologist/philosopher in the late 1800s and early 1900s. He is most famous for his book, "The Varieties of Religious Experience," which was an edited transcript of a lecture series that he gave in Scotland, called the Gifford Lectures. I first heard of him while listening to a program called "In Our Time". By the way, I love listening to "In our Time." They have discussed everything from obscure battles from a thousand years ago to artificial intelligence to the dawn of the iron age to the age of the universe. Here is a link to the program on William James.
If you are interested in reading this book it is quite easy to find a copy. I got mine from Project Gutenberg for the grand price of free. It was preformatted to my e-reader which is even better. I will be taking a chapter at a time and highlighting sections that I particularly liked.