The Popularity of Error, and the Unpopularity of Truth: Having Special Reference to the Old Copernican and Later Newtonian Theory of the Rotundity and Revolution of the Earth is a 19th-century, anti-Copernican pamphlet authored by John Hampden, published around 1869. In summary, the book is a historically significant, albeit anti-scientific, tract aimed at overturning established astronomical models in favor of a literalist, stationary, and flat-earth model, which the author claimed was unfairly neglected by the public and scientific authorities.