In?Modernist Painting, Clement Greenberg regards self-criticism as what makes the modernism. Regarding modern painting, this Kantian recognition calls for a distinguish it from other art forms, which ultimately leads to the recognition of flatness - a “unique and exclusive” factor to modern paintings. Hence, the form in modern painting derives from such pursuits toward flatness and deviates against the 3D art forms such as sculpture, which was the major inspiration for Renaissance paintings. For example, shading and modeling were undermined by the Impressionists, and color became the new focus.

Through this evolution, the form of painting was no longer seen as a picture, but an arbitrary object. The flatness then escaped from the limitation of the real world and developed its depth. Instead of the sculptural illusion, in modern painting, the depth of forms relies on the optical illusion, which we can still travel our eyes through, but is no longer necessarily related to the bodily space where we live.

Rosalind Krauss inSculpture in the Expanded Field?mainly talks about the two types of sentiment: the sublime and the beautiful. It can be referred from his description that the forms which arise these feelings distinguish as well. As the sublimes move people, the according form must be simple and strong. In opposite, the beautiful may be dressed and ornamented, as it charms people.

Peter Eisenman discusses in?Post‐Functionalismthe forms in architecture. Criticizing the long-term consensus of the opposing relationship between form/function, Eisenman suggests understanding the form/function as a dialectical relationship, where various forms of co-existence of the two factors may be possible. Under such assumption, he figures out two tendencies of the form. One is the transformation from pre-existed geometries?and another one as a series of fragments upon which no reference would be found.

A shared exploration in the three readings is how the form could be classified, whether upon the symbol it conveys, the emotion it evokes, or the origin it derives from. Such classifications also implicate the objective toward which the form could achieve. However, it remains to be tested if such analysis approach is also applicable regarding creating new forms.