The twelve and thirteen paragraph discusses Gothic architecture style profoundly as a pointed example. Found on the argumentation of viollet-Le-Duc who highly praised the rigorous application of the system during the twelfth and thirteenth are not caprice or puerile symbolic intents. The author still thinks functionalism play an essential element in appreciation of the Gothic style in a sense. The fussy principles of Christan architecture such as ornamental buttresses conform to their reasons for functions.
However, a style appropriate to the present should be created when applied to contemporary use. When "form follows function" become a law for twentieth century, those expansive, sumptuous structures may never correspond with the modernist style. From "strength, utility, grace" by Vitruvius (active 46-30BC) to "commodity, firmness, delight" by Auguste Choisy (1841-1904), a concise style pursuing full use of function extremely holds a leading post nowadays. The reason of more and more grey-black-and-white color decoration rising are concrete testaments.
The contextual quotation: "all things in nature have a form...it seems ever as though the life and the form were absolutely one and inseparable." "The justification for his theories lay like Sullivan's in his belief that such a system reflected the way of nature - that it was God's way." It reminds the spots on leopards' skin and tail of peacocks which are highly ornamentals but for self preservation and propagation, still fits the maxim.
There is no suggestion that the shapes emerged from their function