Lynn Margulis was the leading proponent of the endosymbiont hypothesis for the origin of the organelles of eukaryotes. We were involved in proving this hypothesis in 1975, using the oligonucleotide cataloguing methods developed by Carl Woese, whose three-domain phylogeny Lynn would resist in favor of her five-kingdom model. Lynn and I became close friends during my sabbatical in Boston in 1977–78, so I was primed to read Jim Lovelock’s first book on Gaia when it came out in 1979 (Lovelock 1979a). It both delighted and infuriated me. I thought the book charming in its description of Life on our planet but deeply wrongheaded about evolution by natural selection. It more-or-less clearly invoked natural selection as the cause of Gaia’s supposed homeostasis-like feedback properties, and seemingly necessary for the maintenance of Life on this planet over the last 4 billion years. So incensed (and ambitious) was I then that I wrote up a little review of the book for the New York Review of Books. Of course they summarily rejected it – I’m not in their stable – and after some soul-searching, and with Lynn’s help, the essay was published in Stewart Brand’s CoEvolution Quarterly, the successor to The Whole Earth Catalog (Doolittle 1981a). Lynn was then happy to disagree, and her counter-essay, along with Jim’s, appeared after mine.