Abstract
The doctrine put forth by G. Frege and now almost universally accepted, according to which a predicate expressing a relative notion has to be supplemented by two (or more) subjects, in order for a statement to arise, appears to be a source of certain difficulties. In the paper, the author defends the view that this doctrine goes against our natural understanding of language, and shows that as soon as an attempt to determine the extension of such “relative” predicates is made, a contradiction in the doctrine is laid bare.