Final answer:
The phrase most associated with Louis Sullivan is "Form follows function," which means that the design of a building or object should be determined by its intended function.
Step-by-step explanation:
The phrase most associated with Louis Sullivan is "Form follows function." Sullivan, a pioneering architect of the modernist movement, strongly believed that architectural design should be primarily based on the purpose of the building.
His influence on modern architecture is significant. Sullivan's ideas suggest that the shape of a building or object should be predicated upon or be reflective of its intended function or purpose. This precept not only applies to architecture but can be seen influencing various design disciplines.
For example, in product design, the dictum implies that products should be designed with their usage foremost in mind, leading to a design that reflects its necessity and function, while also maintaining aesthetic appeal.