A Philosopher Watching a Pair of Butterflies, from The Picture Book of Realistic Paintings of Hokusai (Hokusai shashin gafu). Katsushika Hokusai ?? ??; Japanese, 1760-1849. Date: 1809-1819. Dimensions: 22.8 x 33.9 cm (9 x 13 3/8 in.). Color woodblock