One interesting thing about writing the life of a group is that it pulls you in different ways. It is a question of how far you know you are imposing a pattern and how far it comes from the material itself. Or it's one which you impose from without.
I'm going to talk about my book on the Lunar Society of Birmingham. The society was a group of friends who met once a month. They were inventors, poets, doctors, engineers - all of them concerned with change and new ideas and the coming of industry. And they did enjoy their sociability.
I think what comes from the weaving together of separate lives, which is such a part of the spirit of the age, is that ideas themselves are social. Ideas are probably not produced by individuals; they are more likely to be produced by the exchange of ideas. It takes you away from a romantic idea of the individual genius. How do we think? Do we always think on our own? Or are we always thinking in relation to other people?
Are these individual lives, or can the group have a biography of its own? I think that it can. I think that what probably comes to the fore in a study like this is not the individual achievements - which are all there - but that particular pattern of exchange called collaboration and friendship and competition; and the joint achievement, developing and peaking and waning and fading. It is also linked very much to the interwoven family life which continued, in that Erasmus Darwin's son Robert married Josiah Wedgwood's daughter Sukey - and they were the parents of Charles Darwin. So you feel there's a Lunar lineage, just as there might be in the children of the single biographical subject.