John Locke: The “Jocose Problem” and the Theoretical Foundation of Toleration

Abstract

Two years after the publication of Locke’s An Essay Concerning Human Understanding, he sought advice from his Irish friend, William Molyneux, concerning improvements for the second edition. This discussion resulted in the most substantial alterations of the Essay. Among these changes, Molyneux proposed a “Jocose Problem”—a 17th Century “brain-teaser”—concerning the ability of a formerly blind person to recognize the simple difference between the appearance of a cube and a sphere. Molyneux’s jocose riddle eventually awakened “the greatest philosophic interest” and became the “common center” of attention for 18th Century thinkers like Berkeley, Voltaire, and Diderot (Cassirer 1951, 108-9). The following is meant to reintroduce Molyneux’s Problem by suggesting its origin in the thought of Thomas Hobbes and its bearing on the role of religion in public life. After examining Molyneux’s Problem and its importance for understanding the Essay, I conclude with a brief comparison to Locke’s Letter Concerning Toleration in order to stress its bearing on theoretical and practical considerations for a wide range of political scientists.