 Still, even if there is no real gain in expressive power, one reason to flag the availability of many-sorted quantification is because some of the extensions of classical quantificational logic to be examined below are closely related to certain theories couched in the language of two-sorted logic. In particular, second-order logic and the theory of plural quantification will be each closely related to two first-order two-sorted theories, which lack the expressive resources often attributed to each extension of classical quantificational logic.