Max Weber used the term "iron cage of rationality" to describe what he viewed as a trend in society to move towards a form of bureaucratic rationality that would not realize universal freedom, but rather create an "iron cage" from which there would be no escape. The cause of this trend, Weber believed, stemmed from the expectations and hopes of the Enlightenment thinkers who felt that it was necessary to maintain a strong linkage between the growth of rationality, science and human freedom. Weber saw this as an ironic, bitter illusion.
The expression "iron cage" first became known to English language speakers in the 1930 translation of Weber's "The Protestant Ethic and the Spirit of Capitalism." The original German term used by Weber was "stalhartes Gehause," a translation which has recently been questioned and reinterpreted as a "shell as hard as steel."
Weber wrote that the "iron cage" traps individuals in systems based on rational calculation, teleological efficiency and bureaucratic control. This was, according to Weber, the true end result of the Enlightenment ideal of science and rationality helping mankind to climb up the ladder of history towards what was assumed to be greater wisdom, more freedom and emancipation. Weber believed in idealism, in which things are known only because of the meanings that individuals apply to them. His concern was for the social actions of individuals and the subjective meanings people attached to them within the framework of specific social contexts.