Future archaeologists who come across books from our era would, he says, find it difficult to tell the difference between 'new age' science books full of "junk science" or those containing scientific fact. This is why Lovelock believes that a well-written record of scientific knowledge designed for an intelligent reader is needed. The book should be clear, unbiased and constantly updated. It would explain the theory of natural selection and the principles of medicine, engineering and thermodynamics. It would also cover what we know about the universe. And to guard against future obsolescence, Lovelock argues that such a "survival manual" should be written on paper, not stored on computer.