Throughout his life, through all turmoil, Otto Baum has continuously and consistently championed the freedom of pictorial form. Active primarily in the Stuttgart area, the sculptor recognized, pursued, and applied the potential of pure form in favor of heightened expression. Early on, in the 1920s, he went against the prevailing artistic spirit of the time in sculpture, which was still committed to the mimetic, and turned in expression to a formal language that became increasingly abstract in the course of his creative period. At the same time, an important feature of Baum's art remains his constant sculptural exploration of the degree of abstraction. One of his soul mates in the field of abstracting figurativeness is Hans Arp, whom Baum admired. Baum's constant efforts to achieve a reductive formal language through a freer design approach, as well as his search for archetypal forms in formal orientation to Constantin Brâncuși, culminate in works of perfect form made of the materials bronze, wood or stone. Until then, Baum's works, described by Kurt Leonhard as "cubic" sculptures, were initially still committed to the figurative, but it was not until the postwar years and increasingly in his late work that Baum broke with object-relatedness, his formal language becoming visibly more abstract. In Baum's case, to quote Kurt Leonhard once again, "the depictive principle takes second place to the ur-formative", an assessment that particularly distinguishes the characteristics of his sculptures, since they are based on the striving for the primordial, which he has in common with Willi Baumeister.