Max Weber did not invent the image of the iron cage; it was Talcott Parsons who created that image in preparing the first translation of The Protestant Ethic and the Spirit of Capitalism into English to be published. But that has not prevented it from catching on and even acquiring the status of a popular symbol of Weber's entire view of modern life. Despite its popularity, however, the image does not have a commonly accepted meaning. In part this is because of the creative uses to which it has been put by other scholars, but it is also a result of the fact that Weber himself used the German terms that were the source of Parsons’ translation in a variety of different ways over the course of his scholarly career. The purpose of this paper is to examine those uses to determine whether the meanings they convey add up to something coherent, and if so, what exactly that meaning was.