Alan Chalmers’ book really makes us wonder what we know about the physics of liquids and about how science got to this knowledge. The book provides a great historical reconstruction of the major episodes in the development of modern hydrostatics. It shows how the apparent familiarity of a physical concept mislead and continues to be misleading. The concept of pressure is usually presented as a ‘given’, but it’s far from being self-evident, and its hundred years of intellectual development attest this.