You can't step in the same river twice. The ancient Greek philosopher Heraclitus was famous for his brilliant and provocative sayings, and after 2,500 years his ideas remain as startlingly original as ever. Drawing on examples from science, business, literature and popular culture, the author of the million-selling A Whack on the Side of the Head uses 30 of Heraclitus's epigrams as springboards to dazzling creativity, toppling old habits of thought and firing the imagination.