someone that a pencil was called a "pencil" and pointed to a pencil and said, "pencil," how does the listener know that what one is trying to convey is that the thing in front of me (e.g., the entire pencil) is called a "pencil"? Isn't it possible that the listener would associate "pencil" with "wood"? Maybe the listener would associate the word "pencil" with "round" instead (as pencils are, usually, in fact, round!). Wittgenstein writes regarding several possible "interpretations" which may arise after such a lesson. The student may interpret your pointing at a pencil and saying "pencil" to mean the following: (1) This is a pencil; (2) This is round; (3) This is wood; (4) This is one; (5) This is hard, etc., etc. The Brown Book During the academic year 1934–1935, Wittgenstein dictated to Francis Skinner and Alice Ambrose a text of which three copies were typed and bound. Later it became known as The Brown Book. Wittgenstein contemplated publishing and attempted a German revision, but ultimately abandoned the project as worthless. Possible further book A further item called The Pink Book or The Yellow Book has been speculated to exist, and may be contained in an archive of papers that Wittgenstein posted to a friend of Skinner days after his death. In popular culture In the film Ex Machina, the name of the company designing the artificial intelligence is named 'Blue Book' after Wittgenstein's set of notes, and it is loosely modeled on Google. In the novel “A Philosophical Investigation” by Phillip Kerr a dialogue between a killer identified as neuro-anatomically different and an intuitive female detective occurs. The neuro-anatomical abnormality is supposed to indicate a propensity for murder and individuals are identified and prospectively managed. They are assigned code names in an allegedly anonymised database. The murderer assigned the code name Wittgenstein is tipped into murder by his “diagnosis” hacks into the database and proceeds to murder other abnormal individuals, code named after other philosophers, to prevent them from murdering others. Eventually he is identified but attempts suicide prior to his anticipated trial and punishment by induction of permanent vegetative coma which has replaced the death penalty. Written in the 1990 the novel is a dystopian scientific futuristic fantasy informed throughout by Wittgenstein’s philosophical stances. References Ludwig Wittgenstein Books by Ludwig Wittgenstein Contemporary philosophical literature Philosophy of language literature Analytic philosophy literature Philosophy books Logic books