Final answer:
Karl Marx was a German philosopher and the philosophical leader of communism.
Step-by-step explanation:
Karl Marx was a German philosopher, economist, and sociologist who is best known for his contributions to the development of communism.
He is considered the philosophical leader of communism as he co-authored 'The Communist Manifesto' along with Friedrich Engels.
Marx's ideas and writings have had a profound impact on the world, influencing social, economic, and political thought. However, he was not the leader of the Paris Commune, a French communist rebel, or the first leader of the Soviet Union.
Learn more about Karl Marx and his contributions to communism