In 1963 Gabor published Inventing the Future which discussed the three major threats Gabor saw to modern society: war, overpopulation and the Age of Leisure. The book contained the now well-known expression that "the future cannot be predicted, but futures can be invented." Reviewer Nigel Calder described his concept as, "His basic approach is that we cannot predict the future, but we can invent it..." Others such as Alan Kay, Peter Drucker, and Forrest Shaklee have used various forms of similar quotes. His next book, Innovations: scientific, technological, and social which was published in 1970, expanded on some of the topics he had already earlier touched upon, and also pointed to his interest in technological innovation as mechanism of both liberation and destruction.