This term was popularised by the Harvard biologist Edward O Wilson in 1984 as the title of a book (Biophilia: The Human Bond with Other Species). To him it seemed incontrovertible that we human beings have an innate sensitivity to and need for other living things, because we have coexisted in the closest relationship with the natural world for so many millennia. He defined biophilia as “the connections that human beings subconsciously seek with the rest of life”, and argued that they are determined by a biological need. There may seem to be a smidgen or two of pantheistic tree-hugging environmentalism about the idea (which can hardly be said to be original), but advocates of an emotional, even a spiritual, dimension to our relationship with nature point, for example, to studies that show patients recover quicker if they are exposed to greenery, even pictures of greenery, rather than a purely artificial environment. The concept has been taken up by others, especially Stephen Kellert and Lynn Margulis, and has links with the Gaia Hypothesis that argues that Earth’s ecosystems form a single unit of which the human species is one element. Its reverse is biophobia.