Deliberate ignorance has been known as the 'Ostrich Instruction' in law courts since the 1860s. It illustrates a recurring pattern in history in which figureheads for major companies, political leaders and industry bigwigs plead ignorance to avoid culpability. So why do so many figures at the top still get away with it when disasters on their watch damage so many people's lives? Does the idea that knowledge is power still apply in today's post-truth world? A bold, wide-ranging exploration of the relationship between ignorance and power in the modern age, from debates over colonial power and economic rent-seeking in the 18th and 19th centuries to the legal defences of today, The Unknowers shows that strategic ignorance has not only long been an inherent part of modern power and big business, but also that true power lies in the ability to convince others of where the boundary between ignorance and knowledge lies.