What does the arithmetic proportion relate to in Renaissance proportion theory?

In Renaissance proportion theory, arithmetic proportion is primarily associated with visual harmony. This concept revolved around the idea that mathematical ratios could create aesthetically pleasing relationships within compositions, particularly in architecture, painting, and other visual arts. The Renaissance marked a resurgence of interest in classical ideals, where artists and architects sought to achieve balance and beauty through harmonious proportions.

The use of arithmetic proportions allowed architects to establish relationships between different elements of a building, such as height, width, and depth, ensuring that each part of the structure contributed to the overall visual appeal. By applying these mathematical principles, designers created spaces that were not only functional but also visually coherent and pleasing to the eye.

The other concepts, while significant in their own right, do not capture the central essence of arithmetic proportion in the same way. Natural appearances, for instance, pertain more to realism and the depiction of the world as it is observed, while structural integrity focuses on the physical stability of constructs. Functional spaces address usability and practicality, which, while important, fall outside the primary aim of achieving visual harmony through arithmetic relationships. Thus, the correct association of arithmetic proportion is indeed with visual harmony within the context of Renaissance proportion theory.