This paper critically examines Le Corbusier’s use of natural forms in Notre-Dame du Haut. Ronchamp chapel was designed at a time when modern architecture was criticized for dehumanization and standardization. Le Corbusier tried to overcome this criticism by reinforcing the plasticity of architecture, and based the crab-shaped roof of the chapel on a natural object. He called this ‘synthesis of the arts.’ Natural objects such as seashells, pebbles, and crab shells were at the center of his artistic practice. Le Corbusier sketched natural objects found on the beach and applied their forms to architecture. The ‘chance image’ created by nature was used in his design. He believed that the abundant forms of natural objects, which are difficult to define clearly, would give architecture poetic potential, and he successfully showed the artistic and aesthetic ‘molting’ of architecture in Ronchamp. Le Corbusier fulfilled modern aesthetic demands and simultaneously incorporated architecture into a new practice that could not be dealt with in the Platonic view of the world.