Depends on how one looks. Two considerations: 1. Before the early Ren. art was not art in the modern sense of the term. It was 'applied' art as in being in service to a clear function. 2. During the periods when art was not art for itself few records were kept that discussed it in aesthetic terms or stylistic terms. But when we go back to the 'classic' Greek art era, the peak was, again, about 25 years, 450-425 BCE.
In non-western societies the rule may not apply because art served different purposes and the notion of repetition became an aesthetic ritual....the work celebrated the ritual and existed as a record of the ritual which was the essential art form; .In the west, the ritual or process is subservient to the actual artwork object. It may take a hundred years or more to get to the full expression of an aesthetic or art idea but when it is achieved it lasts one or two 'art' generations....25-30 years. Then decay, or decadence begins. Trouble is, it's very hard to distinguish decay from transformation. In the decay, a new idea is forming. wc Previous to the Renaissance, wasn't the length of "aesthetic stasis" periods longer than 25 years?
