The basic premise of geobiochemistry is that life emerged on Earth where there were opportunities for catalysis to expedite the release of chemical energy in water–rock–organic systems. In this framework, life is a planetary response to the dilemma that cooling decreases the rates of abiotic processes to the point that chemical energy becomes trapped. Catalysis via metabolism releases the trapped energy, and life benefits by capturing some of the energy released. Out of necessity, biochemical processes have geochemical origins, and geobiochemistry asserts that these origins can be revealed by mapping reaction mechanisms onto deep time. We propose five principles that should help guide research in the emerging field of geobiochemistry.