Why does Penguin鈥檚 acclaimed and beautifully designed 'Great Ideas' series include so few books by women? The latest sequence of twenty slim volumes features nineteen male writers (including Shakespeare, Robert Louis Stevenson and George Orwell) - women are represented by a solitary contribution from Virginia Woolf. So who should be on this list of pivotal thinkers? Jenni talks to the editor of the series Simon Winder and Dr Sarah Churchwell, Senior Lecturer in American Literature and Culture at the University of East Anglia.