Only by the time I exited the water, club footed and claw handed, did it hit me that I was hypothermic. The irony of this reckless exercise was that in my swim bag there was a book by Melanie Challenger called Alive: The Hidden Intelligence of the Living World. It is not that Challenger denies the importance of genes; what she questions is the lens through which we read the world. Challenger cites an encyclopaedic range of scientists and philosophers, but her own intellectual guide is Aristotle (she thanks him in the acknowledgments). I’m grateful to them and the way they could quietly read their own bodies, and mine, skilfully relating them to world around us.