Sir Paul Maxime Nurse (born 25 January 1949), is an English geneticist, former President of the Royal Society and Chief Executive and Director of the Francis Crick Institute. He was awarded the 2001 Nobel Prize in Physiology or Medicine along with Leland Hartwell and Tim Hunt for their discoveries of protein molecules that control the division of cells in the cell cycle. Nurse grew up thinking his maternal grandmother was his mother and his mother his sister.

In this book Nurse asks what does it actually mean to be alive? he has spent his career revealing how living cells work. In this book, he takes up the challenge of defining life in a way that every reader can understand. It is a shared journey of discovery; step by step he illuminates five great ideas that underpin biology. He traces the roots of his own curiosity and knowledge to reveal how science works, both now and in the past. Using his personal experiences, in and out of the lab, he shares with us the challenges, the lucky breaks, and the thrilling eureka moments of discovery. To survive the challenges that face the human race today – from climate change, to pandemics, loss of biodiversity and food security – it is vital that we all understand what life is.