A Secret Vice is the title of a lecture written by J. R. R. Tolkien in 1931, given at a conference. Some twenty years later, Tolkien revised the manuscript for a second presentation. It deals with constructed languages in general and the relation of a mythology to its language. Tolkien contrasts international auxiliary languages with artistic languages constructed for aesthetic pleasure.Tolkien also discusses phonaesthetics, citing Greek, Finnish and Welsh as examples of "languages which have a very characteristic and in their different ways beautiful word-form".