Ten years ago, the editor of a leading magazine invited me to lunch. I had been one of his contributors, but we had never met. He broke the ice by asking, 'What is your hobby, Mr. Osborn?' 'Imagination,' I replied. He paused, then wrote on the back of an envelope, 'MY HOBBY IS IMAGINATION.' 'Mr. Osborn,' he said, 'you must do a book on that. It's a job that has been waiting to be done all these years. There is no subject of greater importance. You must give it the time and energy and thoroughness it deserves.' That remark started this book.
