One fundamental characteristic of modernism is a demonstration of progressive innovation. In general, a modernist is someone who tries to develop an individual style by adding to or improving upon the style of immediate predecessors. The modernist belief was in starting with the ideas of the mainstream movement and them innovating from the mainstream to improve upon the ideas of predecessors rather than in breaking away from the mainstream to create something entirely new. However, because there were varying ideas on what constituted the mainstream and because the potential innovations emanating from the mainstream were infinite, modernism under this definition could take a myriad of directions.
A second fundamental characteristics of modernism was the belief that art could and should reflect the reality of modern life and would not, for example, focus on the lives of society's most previleged members or on otherworld entities such as angels and sprites. Though there was agreement among modernists as to the need for art to reflect modern life, there was far less agreement on what actually constituted modern life. Thus, modern artists and architects reflect very different aspects of modern life in their works.