The medical engineer ad earth scientist James Lovelock – still active and alert at 100 – became famous (or infamous) for his Gaia Hypothesis, which suggested that the earth was a self- regulating system (unless, as is now happening, it is threatened by dangerous human behaviours). As he defined it Gaia was “the totality constituting a feedback or cybernetic system which seeks optimal physical and chemical environment for life on this planet”.

He was attacked by some biologists (such as Richard Dawkins, whose views outside biology are to be treated with suspicion) for breaching natural selection theory, which Lovelock has robustly rebutted. He has not been helped by over-enthusiastic Greens, futurists and fantasy writers, who have taken his ideas to mystical heights. Lovelock modestly keeps proclaiming that he knows nothing about spiritualist things and is just an engineer trying to save the planet from environmental disaster.