What should you expect from a companion? Resolute reliability? Occasional inspiration? Whimsical, even capricious distraction? I decided to start with my own pet subject, ethology, one that has a solid presence in the scientific discourse of the second half of the twentieth century, with contributions from Franz de Waal, Jane Goodall, Desmond Morris and Steven Rose, as well as from the three Nobel laureates recognised in 1973.

I lifted the hefty Oxford Companion to the History of Modern Science and found no section headed ‘ethology’. So I went to the front of the book seeking the less technical ‘animal behaviour’. No luck there, either. So to the index. Nothing. What about under ‘psychology’? But there is no such heading! Can psychology be too recent a discipline to qualify? Or insufficiently scientific? Only behaviourism and phenomenology sneak into this category.