THE SCENE: The passage below is typical of medieval scientific thinking, which combines established phenomenon with nonsensical ideas about the world.
THE TEXT: There is a certain rock out in the sea not far from Arklow from which the tide ebbs on one side, while it flows in on the other. Indeed Phoebe [i.e. the Moon] is to such an extent a source and influence on all liquids, that according to her waxing and waning she directs and controls not only the waves of the sea, but also the bone-marrow and brains in all living things as well as the sap of trees and plants. When she is deprived of her full light you will notice that all things lose their fullness. But when she has attained her complete roundness, you will find that bones are full of marrow, head of brains, and other things of sap.
– The History and Topography of Ireland, Gerald of Wales, 12th Century AD
