Born in Bern, the capital of Switzerland, in 1879, Paul Klee was an artist representing the 20th century art scene. He studied paintings from 1898 to 1900 in Munich, Germany. He met Kandinsky in 1911 and participated in the exhibition of the Blue Rider in 1912. His trip to Tunisia in 1914 caused him to explore colors, which eventually started to take effect in his style. Being invited by Walter Gropius, Klee taught at Bauhaus for 10 years from 1921 to 1931. From 1931 to 1933, he also taught at the art academy in Dusseldorf. Since this period, he began producing abstract paintings employing color grids. Klee returned to Bern in 1933 to escape Nazi persecution and died in 1940 before the end of the World War II. Klee developed a poetic world of paintings through simplified figurations and symbols. Spirit in the Tree was originally titled Old Man in a Tree. Has Klee transformed the complex expression of the old man wearing a hat into a spirit when he used simple lines for drawing? Spirit in the Tree drawn with oil on gauze was painted a year after Bust (1922) during Klee’s Bauhaus period.