Keen worked as a freelance journalist for some time, and authored several books about spirituality and religion. He was also featured in the 2003 documentary
Flight from Death. Keen gained notice for his various
self-help books and workshops. In 1991, his book
Fire in the Belly: On Being a Man was published, and was part of a movement which encouraged men to "follow their warrior spirit", as
The New York Times described it. Keen believed that contemporary society and harmed and constrained men and women, and said that a productive movement could provide the same liberation for men as feminist movements could for women. Later, Keen became interested in the
flying trapeze, and said it could provide psychological benefits in his 1999 book
Learning to Fly: Trapeze – Reflections on the Fear, Trust, and the Joy of Letting Go. ==Personal life and death==