This thinker explained different left-wing traditions in Proposed Roads to Freedom, which included the guild socialism this thinker supported. The Beatles became opposed to the Vietnam War after Paul McCartney spoke with this thinker, who organized a tribunal hosted by Jean-Paul Sartre that found the US guilty of war crimes. In 1955, a manifesto named for a German scientist and this thinker condemned the danger of nuclear weapons. This thinker advocated for four-hour workdays in his essay “In Praise of Idleness.” This thinker’s opposition (10[1])to American entry into World War I resulted in his dismissal from Trinity College. In a non-political essay, this thinker distinguished between the present King of England and the present King of France as different kinds of definite descriptions. For (10[1])10 points, name this British philosopher who wrote On Denoting. ■END■ (10[1])