How did Piet Mondrian’s work help shape the development of modern abstract art?

Piet Mondrian was a pivotal figure in the development of modern abstract art, primarily through his leadership in the Dutch movement known as De Stijl ("The Style").12

Mondrian’s work helped shape abstraction by advocating for the complete rejection of visually perceived reality as subject matter. He sought to move beyond traditional representation by reducing painting to its most fundamental elements: straight lines, right angles, primary colors, and the neutrals of black, white, and gray. This approach, which he termed Neoplasticism, aimed to express a "pure" reality and the harmony of the universe rather than depicting individual objects.1324

His evolution toward total abstraction was influenced by his early exposure to Cubism and theosophical ideas regarding the mathematical construction of the universe. By mobilizing line, form, and hue to serve the embodiment of "plastic expression," Mondrian established a rigorous formal vocabulary that freed art from representing momentary perceptions or the artist's personal temperament. His theories, disseminated through the De Stijl journal and his writings, profoundly influenced the trajectory of 20th-century nonrepresentational art.5431