We were delighted to receive your holiday card just prior to our trip to Cairo and Alexandria. We brought books, naturally, to the extraordinary new library but failed – as I forgot to bring any Gaia books. Not, after 5000 years, too late. I’ll send them from home.

The original essay in English on the concept of autopoiesis – introduced as a criterion by which to distinguish living from non-living systems – is “Autopoiesis: the organization of living systems, its characterization and a model” (Varela et al. 1974).359 The authors published that essay in the fifth volume of BioSystems; Margulis published an essay in BioSystems’ sixth volume (Margulis 1974a). As it happens, then, the concept of autopoiesis was introduced into Anglophone science in a journal that Margulis attended to, published in, and then co-edited, from 1983 to 1993. In December 1985, Margulis dilated on this topic in a letter marked under the date as “en route Pittsburgh–Boston.” Perhaps, as with Letter 77 a decade earlier, she was writing Letter 169 while on or waiting for a flight home. It appears to record Margulis’s impromptu responses to draft portions of a Lovelock manuscript. It also documents the intensity with which she took up the issue of autopoiesis at this stage of her theoretical engagement with Gaia theory. Lovelock did not reciprocate her enthusiasm in this regard.360

I’m beginning to wonder about the Boston mail system. You don’t seem to receive the letters I write or they are so delayed that their contents seem irrelevant. Mail to other USA destinations always travels without problems. Although I have noted that mail to and from more distant places such as New Zealand, Japan, and S. Africa takes less time to travel. In my more paranoid moments I imagine the more fanatic of the Irish Patriots – who no doubt run the Boston mail – striking their blow against Cromwell by blighting the mail from England. Let’s hope this one runs the gauntlet.

Crispin faxed to say that you had asked for our telephone number and that he could not give it you. I owe you an explanation. For several reasons – not least that I am truly terrified of telephones and their ring is to me as menacing as the dry noise of a rattlesnake – we keep our number for those of our family who might need to reach us urgently.

I first encountered Gaian ideas as an 18-year-old undergraduate returning home for Christmas 1991 from a first term studying Natural Sciences at the University of Cambridge. I had been thrilled to make it to Cambridge from my local comprehensive school. Science was my calling, having avidly consumed popular science throughout my teenage years. But the university seemed full of over-confident rich kids keener on making a social impression than an intellectual one. Looking back, it was uncannily like Tom Sharpe’s hilarious book Porterhouse Blue.580 Meanwhile, I was stuck in the library until 11:00 pm most nights trying to get on top of the mathematics and physics curriculum. I was also troubled by the ozone hole, global warming, Amazon deforestation, and the overall sense that humans were destroying the Earth. Yet the best our lectures could suggest as a career path was “chemical engineer.” Into this mental melting pot my dad gave me Gaia: A New Look at Life on Earth and The Ages of Gaia: A Biography of our Living Earth as Christmas presents. I devoured both and was captivated by this new world view. At the end of Ages of Gaia, Jim Lovelock calls for practitioners of planetary medicine and asks: “Is there a doctor out there?” I decided to answer Jim’s call: In early 1992 I wrote him a letter saying I would like to join the quest and research Gaia when I graduated. He generously invited me to visit Coombe Mill in summer 1992.

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.

With Lovelock’s move from Bowerchalke to Coombe Mill, The two years from 1977 to 1979 were the quietest in all my time as an independent. To travel anywhere was now much more difficult. It was an hour’s journey by car to Exeter station and Plymouth airport, and then three or four hours to London. I still had my four sponsors: Shell, HP, MOD, and NOAA – but the settling in at Coombe Mill occupied most of my time.246

As I write this, I am 84 years old. When I was 42, precisely halfway through my life so far, my contemporary, the microbial ecologist Wolfgang Krumbein, drew me into the Gaia debate. That was in the autumn of 1979, the moment when Lovelock’s seminal Gaia: A New Look at Life on Earth made its appearance. Sadly, Wolfgang passed away a couple of months ago, but that does not alter the fact that both our lives were split in two equal halves, before and after Gaia. Gaia hit me with the strength of a lightning bolt, but unlike lightning, the impulse of Gaia persisted. I have chosen to delve into my own humble story to find out about the reason for this remarkable commitment. Why was I faithful to an idea that most scientists rejected when it appeared on the scene?

Book 5 is oriented on the southern and eastern coasts of the Mediterranean. The discussion includes the known portions of the continent of Africa (essentially as far south as the tropics, 1–46), and then continues to Egypt, which is considered a region separate from Africa (47–64). After an account of Egypt that is limited to its more northern portions, the narrative moves through coastal Asia, from western Arabia north into Judaea and Phoenicia, and to Syria, with a digression on the Euphrates River (65–90). Then there is consideration of the coastal territories of Asia Minor, from Syria around as far as the Troad (Troas) and the Thracian Bosporus (91–127). The book concludes with the Aegean islands not previously discussed (those close to the Asian shore), some of the inland territories of western Asia, and the islands in the Propontis (128–151). The end of the book leads directly into the beginning of Book 6, continuing the examination of northern Asia Minor.

Book 3 of the Natural History, the first geographical book, confines itself to southern Europe, from the outlet of the Mediterranean at the west to the mouth of the Danube at the northeast, excluding the Greek peninsula. After a brief introduction about geography and Pliny’s technique (1–2) and comments about Europe as a whole (3–5), the narrative moves through Hispania (6–30), Gaul (31–7), and Italy from the Alps to Sicily (38–138). The Italian portion is nearly two-thirds of the book, which concludes with the regions east of the Adriatic as far as the Danube (139–51). Discussion of mainland Greece is reserved for the following book (NH 4.1–39), whose beginning follows directly on the end of Book 3. The account of the lands west of Italy is limited to the Mediterranean coasts: the remaining portions of the Iberian peninsula and Europe are examined in Book 4 (94–120).

Book 6 discusses the portion of the continent of Asia that had not been examined in Book 5, beginning at the Thracian Bosporus, where Book 5 ended (5.151). Now Pliny continued from the Bosporus around the Asian shore of the Pontus Euxinus, or Black Sea (1–24), with some diversion into the interior of Asia Minor. He then moved into Armenia and the Caucasus (25–35) and the Caspian region (36–49). After a consideration of the extreme north and east of the known world (50–5), the Natural History focused on India, Taprobane, and Ariana (56–106). Returning west, the account moves into the Persian plateau and Mesopotamia (107–141), and then the part of Arabia not previously discussed (142–77), followed by Aethiopia (178–97), and concluding with various islands (198–205). The final portion of the geographical books of the Natural History is about terrestrial parallels (206–20).

C. Plinius Secundus was born at Comum (modern Como) in late ad 23 or sometime the following year. Comum, at the southern end of Lake Larius (modern Lago di Como), had been an obscure Celtic village until a century previously, when the Romans established a presence there. Virtually nothing is known about Pliny’s youth or education, but by ad 47 he had embarked on an equestrian military career in Germania under the command of Cn. Domitius Corbulo. He had returned to Rome by the ad 50s, and seems to have remained relatively obscure during the principate of Nero. But with the accession of Vespasian – whom he already knew – in ad 69 he returned to public service and became a procurator (financial officer), with positions in various locations, including Narbonensis, Tarraconensis, Belgica, Africa, and perhaps elsewhere. He became a close advisor to the emperor, confering with him on a daily basis when in Rome. He also practiced law. Eventually he became fleet commander at Misenum, the Roman naval base established by Augustus at the end of the long peninsula that forms the western side of the Bay of Naples. His sister Plinia and her son, also C.