Automatic author identification is a branch of computational stylometry, which is the computer analysis of writing style. It is based on the idea that an author’s style can be described by a unique set of textual features, typically the frequency of use of individual words, but sometimes considering the use of higher level linguistic features. Disputed authorship studies assume that some of these features are outside the author’s conscious control, and thus provide a reliable means of discriminating between individual authors. Many studies have successfully made use of high frequency function words like “the”, “of” and “and”, which tend to have grammatical functions rather than reveal the topic of the text. Their usage is unlikely to be consciously regulated by authors, but varies substantially between authors, texts, and even individual characters in Jane Austen’s novels. Using stylometric techniques, Oakes and Pichler (2013) were able to show that the writing style of the document “Diktat für Schlick” was much more similar to that of Wittgenstein than that of other philosophers of the Vienna Circle.