ABSTRACT
This chapter recounts a standard narrative of the path to Leo Szilard's thought experiment and its subsequent development. It argues a failed thought experiment and the locus and origin of enduring confusions in the subsequent literature. In the standard view, Szilard's thought experiment was the initiating stimulus for a new tradition in physics. Until it drew attention to the role of information, one is supposed to believe, it was impossible to understand the necessity of failure of James Clerk Maxwell's demon. The thought experiment illustrated how a quantitative relation is possible between information acquired or, later, erased and thermodynamic entropy. The principle that governs this relation, whichever it might be, forms the foundation of a new science of the thermodynamics of information or computation, with the exorcism of Maxwell's demon its signal achievement. The chapter gives a dissenting, less celebratory view of the thought experiment.
