Ludwig Ritter von Köchel since undergone revisions. Mozart's works are often referred to by their K-numbers ("cf." opus number); for example, the "Jupiter" symphony, "Symphony No. 41" K. 551. Moreover, Köchel arranged Mozart's works into twenty-four categories, which were used by Breitkopf & Härtel when they published the first complete edition of Mozart's works from 1877 to 1910, a venture partly funded by Köchel. He also catalogued the works of Johann Fux. Ludwig Ritter von Köchel Ludwig Alois Friedrich Ritter von Köchel (; 14 January 1800 – 3 June 1877) was an Austrian musicologist, writer, composer, botanist and publisher. He is best known for
19th-century philosophy Stuart Mill promoted the idea that actions are right as they maximize happiness, and happiness alone. Developed by Karl Marx and Friedrich Engels in the mid-to-late-19th Century, Marxism is a sociopolitical and economic view based on the philosophy of dialectical materialism, which opposes idealism in favour of the materialist viewpoint. Marx analysed history itself as the progression of dialectics in the form of class struggle. From this it is argued that "the history of all hitherto existing society is the history of class struggles." According to Marx, this began with the phase of primitive communism (hunter-gatherer society), after which the