Functionalism has a prominent place in 20th-century aesthetics. The focus on material and form is a main key to the concept's far-reaching importance. A combination of material and form is the precondition for art in general and is thus not in itself unique to the period of time discussed in this book. Functionalism, however, represents a heightened awareness of these two aspects: an artistic concept of truthfulness allows material and form to manifest themselves according to what may be recognized as their idiosyncratic premises. A firm belief in the inevitable “will” of the material and the universal validity of pure, non-ornamental forms is crucial to this understanding. In this study, functionalism has been preferred to potentially competing concepts, because it compiles various characteristics of a conceptual complexity pertaining to important aspects of 20-century art. As a term, functionalism delimits the concept by directly referring to a set of essential features. Function becomes a key designation and the common denominator for a profound understanding that also encompasses ideas of the function of art in terms of the individual and society. Applying the concept presupposes that it is freed from the constrictions of a narrow view that only sees a functionalist object's utilitarian value.

Functionalist thinking is directed towards what material and form really are. Several important features underpin the functionalist recognition of form and material. These basic traits also shape attitudes to the process of artistic elaboration in a wider sense. Moreover, emphasis is placed on what the components of artistic creation actually are, after they have escaped from the twilight of Romanticism and been brought into the daylight of the 20th century. In the first part of that century, a search for authenticity becomes the driving force in a broad, aesthetic shift from the concept of beauty to the concept of truth. Although these notions originate from the same root, truthfulness becomes a new evaluation criterion and, accordingly, it is given decisive emphasis. The term “beautiful” is regarded as closely related to pleasant, pretty, and lovely, while “truthful” can also comprise what is unfamiliar, unpleasant, and ugly.