Autologicality is an interesting linguistic phenomenon. It was first described in 1908, by the German philosophers Kurt Grelling and Leonard Nelson, who were trying to solve a paradox first laid out by the English philosopher Bertrand Russell. Without getting into it, let's just summarize by saying that Russell had observed some years earlier that if you think about sets that contain themselves and sets that don't contain themselves, you're going to have a hard time classifying the set that only contains sets that don't contain themselves. Does that set contain itself? Think about it. In any case, Grelling and Nelson were working on this and realised that some words aptly describe themselves ("short," "English") and some don't ("long," "ingles"). They called the first "autological," and the second "heterological."

A startling variant of Russell's paradox, called "Grelling‘s paradox", can be made using adjectives instead of sets. Divide the adjectives in English into two categories: those which are self-descriptive, such as "pentasyllabic", "awkwardnessful", and "recherche", and those which are not, such as "edible", "incomplete", and "bisyllabic". Now if we admit "non-selfdescriptive" as an adjective, to which class does it belong? If it seems questionable to include hyphenated words, we can use two terms invented specially for this paradox: autological (= "self-descriptive"), and heterological (= "non-self-descriptive"). The question then becomes: "Is ‘heterological’ heterological?" Try it!

Some adjectives have meanings which are predicates of the adjective word itself; thus the word 'short' is short, but the word ‘long' is not long. Let us call adjectives whose meanings are predicates of them, like ‘short', autological; others heterological. Now is 'heterological' heterological? If it is, its meaning is not a predicate of it; that is, it is not heterological. But if it is not heterological, its meaning is a.predicate of it, and therefore it is heterological. So we have a complete contradiction.