Thomas Kuhn

‘Is there life on Mars?,’ asked David Bowie, and would not stay for an answer. The astrobiologist Steven Benner has an answer – which is that Mars not only has had life but still does. The first part of that answer is broadly accepted; the second remains highly contentious. His book is a scattershot plea for increased attention to be paid to searching for evidence – or, as he sees it, more evidence. The stakes are high. As he says in his introduction, if life exists only on Earth, that’s a coincidence; if it exists on Earth and a close neighbour, that’s the start of a pattern. Mars has always excited the imagination. No one has ever speculated hubristically about the chances of anything coming from Mercury. C.S.

The world divides between creeps and jerks. History can be seen as a long, unedifying creep, or what one of Alan Bennett’s characters called ‘one fucking thing after another’. Alternatively, it might be seen as consisting of jerks – that’s to say, big events that revolutionise the world (the invention of the printing press, the advent of steam, the French Revolution, Hiroshima, Tim Berners-Lee’s creation of the world wide web). The latter position is essentially that of the philosopher Alain Badiou. The French Maoist maintains that the significance of events that stand out from the usual blah of history can only be grasped retroactively – vindicating Zhou Enlai’s reply when asked in 1972 about the significance of the French Revolution: ‘Too early to say.