Swiss-German painter and Bauhaus teacher whose nearly 10,000 small works — watercolors, oils, drawings, prints, almost all on paper or small panels — constitute one of the great singular bodies of 20th-century modernist painting, and whose teaching notebooks are, for the serious student, among the foundational texts of modern art pedagogy. Klee came to the Bauhaus in 1921 at Gropius's invitation, having been a central figure in the Blaue Reiter group with Kandinsky and Franz Marc before the First World War, and taught there (first at Weimar, then Dessau) for a decade.
His courses on "pictorial form theory" (bildnerische Formlehre) were the most philosophically ambitious attempt any modern painter has made to state systematically how a picture is made — what a line does, how a plane emerges from accumulated lines, how rhythm and polyphony transfer from music to painting, how motion and weight and growth can be figured in color and form. The lecture notes became, through his students Jürg Spiller and others, the posthumous Pedagogical Sketchbook (Pädagogisches Skizzenbuch, 1925) — a Bauhaus book that remains genuinely usable — and the two-volume The Thinking Eye / The Nature of Nature (1956, 1970), which is among the most serious primary documents of modern painting.
The work itself — Angelus Novus (1920), which Walter Benjamin owned and wrote into his "Angel of History" in the ninth thesis on the concept of history; Twittering Machine (1922); the late Death and Fire (1940) — does something unlike anyone else's: small, child-like at first glance, cosmologically serious on longer looking, humorous in a register that in any other hand would be merely whimsical. The Nazis declared him a "degenerate artist" in 1933; he returned to Switzerland, contracted scleroderma, and worked with increasing urgency through his last five years. The late works are his greatest.