evidence: Did Einstein really say that? [...] Beyond his towering contribution to physics, Albert Einstein was an avid commentator on education, marriage, money, the nature of genius, music-making, politics and more. His insights were legion, as we are reminded by this month’s publication of volume 15 in The Collected Papers of Albert Einstein. Even the website of the US Internal Revenue Service enshrines his words (as quoted by his accountant): "The hardest thing in the world to understand is the income tax." "There appears to be a bottomless pit of quotable gems to be mined from Einstein’s enormous archives," notes Alice Calaprice, editor of The Ultimate Quotable Einstein (2011); one detects a hint of despair. Indeed, Einstein might be the most quoted scientist in history. The website Wikiquote has many more entries for him than for Aristotle, Galileo Galilei, Isaac Newton, Charles Darwin or Stephen Hawking, and even than Einstein’s opinionated contemporaries Winston Churchill and George Bernard Shaw.