During Kristek’s visits to Arno Lehmann (1905–1973) who was living in Salzburg, Kristek drew from conversations on philosophy and the meaning of symbols in sculpture. In 1973, when Lehmann died, Kristek created the wooden sculpture Soul. The bottom part resembles the combat of natural forms from which the two strongest branches are growing. Yet the evolution stops at one of the branches – it is defeated by the winning branch crowned with a sphere as the utmost geometric shape and concentrated energy. Kristek deliberately adopted Lehmann’s symbol of sphere.
The surface of the sculpture is treated with flame. In an interview with Sven Mueller for the German magazine Collage (Das kunstvolle Leben des Bildhauers: Lubo Kristek, Collage 3/1976), Kristek stated the following on this method: ‘In my way of creation, human writing on the surface is intentionally suppressed. In fact, with fast flame oxidation, the roundedness and little surfaces are signed by nature itself.’
In 1987, the sculpture Soul was exhibited in the Munich Residenz.