 The status of plural quantification remains controversial. All parties agree that plural locutions are systematically used in natural languages, but there is no consensus as to whether or not the truth conditions for plurally quantified sentences should ultimately involve covert reference to complex objects of some kind or another. The entry on  plural quantification  discusses some reasons generally offered in favor of the irreducibility of plural quantification to singular quantification over sets. But an influential argument against the identification of plural quantification and singular quantification over sets traces back to Boolos 1984, which claims that the following two sentences differ in truth value when we let the domain of quantification include all sets there are: