  As the medievals interpret it, this definition identifies relations in terms of the predicates by means of which they are signified. Medievals refer to the predicates in question as ‘relative terms’ (ad aliquid or   relativa),[9]   and understand them, roughly speaking, as those terms whose true predication requires a comparison to something other than the subject of which they are predicated. Thus, ‘taller’ (maius) counts as a relative term because when we assert of something that it is taller—that is, when we predicate the term ‘taller’ of it—we necessarily do so in comparison to something else. We don’t say merely that Simmias is taller; we say that he is taller than Socrates, or Theaetetus, or the average man. Similar remarks apply to ‘double’, as well as to all other relative terms. Borrowing on the medievals’ behalf the notation of first-order logic, we can make this characterization of relative terms precise by saying that a term F is relative just in case a predication of the form ‘Fx’ is more perspicuously represented as a predication of the form ‘Rxy’. (If a term is not relative, then the medievals say that it is absolute.)