Rudolf Carnap (/ˈkɑrnæp/; German: [ˈkaɐ̯naːp]; May 18, 1891 – September 14, 1970) was a German-born philosopher who was active in Europe before 1935 and in the United States thereafter. He was a major member of the Vienna Circle and an advocate of logical positivism. He is considered "one of the giants among twentieth-century philosophers."