To be confirmed: In March 1997 Greg said he had been writing a book for the last 2 years on the music industry from a band's perspective and hoped to have it done in the following 8 months. He had then finished 160 pages of 1st draft text.

In 2003, Greg wrote his Ph.D. dissertation called 'Monism, atheism, and the naturalist worldview: Perspectives from evolutionary biology', which could be obtained through a website dedicated to his project: http://www.polypterus.com.
Greg: "I said I would sign the first 500 copies but when I came to the 501st order I didn't have the heart to forego signing it. Therefore, I will continue to sign all books ordered through December, 2004. It has been a great uplifting surprise that so many are ordering the book. I am glad we have so many thoughtful fans interested in life's large issues."
The first 500 copies were signed in black ink. Starting with number 501 all copies were signed in blue ink.
In 2010 Greg's dissertation was rereleased (also in support of 'Anarchy Evolution') with an added an afterword.

In 2006, a book called 'Is Belief in God, Good, Bad or Irrelevant?: A Professor and a Punk Rocker Discuss Science, Religion, Naturalism & Christianity' was published by Preston Jones, a history professor from a Christian University. The book features an email correspondence between Jones and Greg Graffin, in which the two discuss their views on several scientific and religious topics.

In 2010 Greg published a book called 'Anarchy Evolution'. This book was written together with Steve Olsen and is published by HarperStudio. It touches upon subjects as naturalism, science, faith, art and, of course, Bad Religion.
Greg: "I spent 30 years with my band writing about a society that circled around religion because the band's name is Bad Religion. We always thought we would write topical material and hopefully provoke people to think a little about some of these challenging issues.
Bad Religion was a good forum to do that, but I was also studying evolution for those 30 years and instead of religion, I used science to make sense of the world. It might seem kind of weird to some people that someone would study science and sing punk rock at the same time. 
But it's true, those two things developed side by side in my life and finally, after 30 years, I wanted to make some sense of it. For myself, really. To make a coherent world view out of the two streams of consciousness."

In April 2011, Greg mentioned in an interview that he has plans to work on his next book, titled "The Population Wars," which he said will be "a bit more in depth about the process" of evolution.
Greg: "It's about change, and change is a good metaphor for the way we live our lives," he said. "So it's going to be another general interest book that talks about change, but it will be a look at life from a population perspective."^[1]
It will not be released until 2014. The subtitle is "The Biological Basis Of Co-Existence".^[2]

References