Carnap's Logical Syntax of Language (1937) contains an unfortunate passage, the ‘Babylon passage’, explaining what it is for a linguistic expression to be about a subject matter. Past criticism has only addressed Carnap's mistaken claim that the occurrence of a denoting term is necessary and sufficient for a linguistic expression to be about the denotatum. But the passage contains further problems: a form‐object confusion due to the ambiguity of ‘lecture’; a use‐mention problem with the word ‘Babylon’; and finally, the fact (...) that its key sentence ????1 is a counterexample to Carnap's own definition of aboutness. These flaws notwithstanding, the passage's ‘non‐formal consideration’ that a statement's truth or falsity should matter to our knowledge about the subject matter's properties, is an important contribution to aboutness theory. This paper discusses all these pros and cons of the passage in depth with a view to their consequences for current work on subject matter. (shrink)