I’d have to say Peter Medawar’s The Art of the Soluble: Creativity and Originality in Science, which I purchased out of curiosity when I was in my early 20s, and devoured. It made science seem like a grand, romantic adventure yet also fun: something not “professionalised” into another nine-to-five job, as is increasingly the case these days. I also love his vitriol: in one place he refers to scientists who think science consists of unprejudiced data-gathering without speculation as “cows grazing on the pasture of knowledge”. In another, he calls a certain class of explanations in science “analgesics that dull the ache of incomprehension without removing the cause” – a common syndrome in the field of psychology, I might add.

If I was allowed a second book it would be The Expression of the Emotions in Man and Animals by Charles Darwin, a perfect balance of speculation and astute observation, more readable and full of ideas than many recent tomes on emotions.