Already in the period of widespread spread of functionalism throughout the world, signs of its differentiation are becoming more and more obvious. Simultaneously with the departure from the stylistically unified form of functionalism, the first criticisms of his one-sided utilitarian approach to architecture appear in individual works. Some architects already at the end of the 30s began to consider the functionalist system of shaping and its theoretical concept obsolete.
One of the first signals to criticize the theoretical concept of pre-war functionalism was the idea of organic architecture, formulated by F.D. on the other hand, from a reaction to the rationalism prevailing in American architecture. The conceptual core of the theory of organic architecture was the requirement for a balance between its material and mental sides, as well as a new understanding of the actual essence of the structure, which Wright saw not in the walls and ceiling, but in the space they formed and life in it. However, this idea was expressed by the ancient Chinese philosopher Lao Tzu. Wright understood the word "organic" in the meaning of "integral", "internally whole", He called for the creation of a harmonious space that meets its purpose, economical, creating an atmosphere of poetic peace, and not dead solidity. A building of this type was E. Kaufman's villa "Waterfall", the shape of which naturally grows out of a rocky terrace, as well as Wright's own dwelling "Teilisin West" in Arizona (1938), which organically included natural forms. It was also the winter residence of his private architecture school, Teilisin Partnership.
In the 40s, individualism and artistic originality led Wright to new functional and formal structures, similar in nature to the constructive structure of some natural forms. The crystal and the spiral became at that time a motif often found in Wright's work.
Among his works stands out the complex of buildings of the administrative and research center of the firm "Johnson" in Ransine (1936-1939), solved almost exclusively on the basis of soft curves. Of the post-war works, the building of the Guggenheim Museum in New York (Museum of Modern Art) should be noted, designed in the form of a rising and expanding reinforced concrete spiral. Wright's pronounced individualism and the tenacity with which he sought ways to make functional and formal solutions of modern architecture more natural83 made a deep impression after the Second World War, having a strong influence on the further development of world architecture.
The Italian theoretician B. Dzevi became a prominent proponent of this idea in the 1940s and 1950s. He summarized his thoughts on organic architecture, the features of which derive from the forms and mode of life, in his book Towards Organic Architecture (1945). In response to criticism of the one-sidedness of functionalism, there were attempts to further theoretical development and improvement of its concept through attention to mental and biological functions.
R, Neutra, and the Czech architect L. Jacques, who considered the surrounding nature as the widest and most natural human habitat - "habitable nature" (1940-1947), had similar views on the natural living qualities of the natural landscape to Wright's views. The idea of organic decentralization of the city was put forward in the 1940s by E. Saarinen (City, 1943), who, guided by this idea, already in 1913 developed the urban planning solution for Tallinn, and in 1918 for Helsinki.