Jim Lovelock was an unusual PhD supervisor. He was listed as a “visiting professor” at the Department of Engineering and Cybernetics in Reading. In truth, however, he never actually visited, so during the three years from 1975 to 1978 when I was his only student, it was I who visited him, usually once or twice in a semester. This involved a four-hour drive to Cornwall, so I would stay overnight with Jim and Helen at Coombe Mill. That meant that I would have Jim’s attention for a full afternoon and evening, which was an intensity of interaction that few PhD students are lucky enough to have with their supervisor. On these trips we would discuss not only what I was doing, but everything else that interested us and especially everything about Gaia – he was writing the first book at the time.