It seems indisputable that there are holes. For example, there are keyholes, black holes and sinkholes; and there are holes in things such as sieves, golf courses and doughnuts. We come into the world through holes, and when we die many of us will be put into specially dug holes. But what are these holes and what are they made of? One of the big philosophical questions about holes is whether they are actually things themselves or, as the German-Jewish writer Kurt Tucholsky suggested in ‘The Social Psychology of Holes’ (1931), whether they are just ‘where something isn’t’. To help us investigate this issue, let us first dissect the anatomy of the hole.