The following excerpt is from Godel, Escher, Bach: an Eternal Golden Braid by Douglas Hofstadter.
Divide the adjectives in English into two categories: those which are self-descriptive, such as "pentasyllabic", "awkwardnessful", and "recherché", and those which are not, such as "edible", "incomplete", and "bisyllabic". Now if we admit "non-self-descriptive" 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!
What Hofstadter is describing is a famous variation of Russell's Paradox known as The Grelling-Nelson Paradox. Both Hofstadter and Grelling seem to be concerned with how one should classify "heterological", and makes no mention of which of the two categories "autological" falls into. So my question then, is "autological" an autological adjective, or a heterological adjective? Or is the answer to this question yet another paradox implied by Grelling's original question about "heterological"?