In Professor Susskind's lecture 7 on Classical Physics, he discusses Liouville's Theorem. He said that a consequence was that points in the phase space can not coalesce and lose their identity. In Professor Susskind's book, Black Hole War, he discusses why destruction of information at the event horizon of a black hole would violate conservation of information. My question is: The conservation of information in Liouville's theorem and the conservation of information in the black hole debates; are the the same concept? The reason I ask, is that in Black Hole War, Susskind says that violation of conservation of information would violate the most fundamental laws of physics. Yet is is fuzzy what kind of information he means, and which fundamental laws mandate conservation of information.