This book may not change your life. But if you have a tendency to be messy and have already broken your new year resolutions to be neater in future, it will certainly make you feel better about your natural inclinations. Untidiness, hoarding, procrastination and improvisation are not bad habits, the authors argue, but often more sensible than meticulous planning, storage and purging of possessions. That is because the tidiness lobby counts the benefits of neatness, but not its costs. A rough storage system (important papers close to the keyboard, the rest distributed in loosely related piles on every flat surface) takes very little time to manage. Filing every bit of paper in a precise category, with colour-coded index tabs and a neat system of cross-referencing, will certainly take longer. And by the end, it may not save any time. Your reviewer's office is easily the most untidy in The Economist (not entirely his own work, it should be said, thanks to the heroic efforts of his even untidier office-mate). But when it comes to managing information, there seems to be no discernible difference in the end result. The authors of this book trawl the furthest reaches of psychology, management studies, biology and physics to show why a bit of disorder is good for you. Chiefly, it creates much more room for coincidence and serendipity. Alexander Fleming discovered penicillin because he was notoriously untidy, and didn't clean a Petri dish, thus allowing fungal spores to get to work on bacteria. He remarked wryly on visiting a colleague's spotless lab: 'no danger of mould here'. It can also help make sense of things. Hearing depends on random movement of molecules: when they coincide with sounds from outside, they are strong enough to stimulate the inner ear. A bit of background noise on the phone enables our ears to filter out echoes. A slightly mushy photograph can be easier to understand. Music and art depend on mess. Procrastination makes sense too. America’s Marine Corps, the authors repeat (several times), never makes detailed plans in advance. Leaving important things to the last minute reduces the risk of wasting time on things that may ultimately prove not important at all. The authors are witheringly contemptuous of the bogus equation of tidiness and morality—for example in corporate 'clean desk' policies. Disorder and creativity are so closely linked that any employer who penalizes the first sacrifices the second, they argue. America's professional organizers, a thriving and lucrative cult of tidiness coaches, are merchants of guilt, not productivity boosters. It's all fine, up to a point. But the book has two weaknesses. One is that it overstates the case. The case for tidiness in some environments—surgery, a dinner table or income tax returns—is really overwhelming. The other is that the book is a bit repetitive and disorganized. Even readers who love mess in their own lives don't necessarily like it in others. Paraphrase the sentence 'the tidiness lobby counts the benefits of neatness, but not its costs'. (para. 2)