When flying back from an environmental conference in the Seychelle Islands, looking down over the Nile River at 30,000 feet, he realized that he was not a theologian, but rather a “geologian.” With this term, he viewed himself as a human being who emerged out of eons of Earth’s geological and biological evolution and was now reflecting on our world. This reflection was a way to reinvent the human at the species level.
This notion of reinventing the role of the human was enhanced when in 1982 Thomas met Brian Swimme who came to the Riverdale Center for a year of study. Coming from the Pacific Northwest and having earned a doctorate in mathematical cosmology at the University of Oregon, Brian was the ideal partner for collaboration. Thomas’ years of study of world history and religions was paralleled by Brian’s comprehensive study of evolutionary history. From an intense decade-long collaboration including research, lectures, and conferences there emerged in 1992 the jointly authored book, The Universe Story. This was the first time the history of evolution was told as a story in which humans have a critical role.
After Thomas retired from teaching at the age of 64, he began some of his most significant writing in the area of evolutionary cosmology in relation to the ecological crisis. The Dream of the Earth was published in 1988, The Great Work in 1999, Evening Thoughts in 2007, The Christian Future and the Fate of Earth in 2009, and The Sacred Universe in 2009. These books elaborated on the "new story" of our shared cosmological journey.