The sheer number of Renaissance treatises tells us something about the nature of a cultural movement. One tends to think of what goes by that name as comprising a handful of geniuses with a group of admirers, patrons, and articulate supporters whose names appear (so to speak) as footnotes in smaller type. Actually, it is a large crowd of highly gifted people---the mass is indispensable. This is a generality. And these many co-workers must be great talents, not duffers. They may be incomplete or unlucky as creators, their names may remain or turn dim, but in retrospect we see that this one or that contributed an original idea, was the first to make use of a device. Together, by what they do and say, they help to keep stirred up the productive excitement; they stimulate the genius in their midst; they are the necessary mulch for the period's exceptional growths.
This reflection goes some way toward answering our question when we wonder what conditions bring about great artistic periods, seemingly at random, here or there, and for a relatively short time. It is not, as some have thought, prosperity, or wise government support, or a spell of peace and quiet---Florence at its height was in perpetual conflict inside and outside. The first requisite is surely the clustering of eager minds in one place. They may not be on the spot to begin with; they come mysteriously from all over, when some striking cultural event bruited abroad, some decisive advance in technical means, draws them to its place of origin. Like the spread of the revolutionary temper, the feverish interest, the opposition, and the rivalry among artists working, comparing, and arguing, generate the heat that raises performance beyond the norm. It takes hundreds of the gifted to make half a dozen of the great. The late-discovered genius who by mischance had to work alone in a remote spot is a sad survivor of solitude and is often maimed by it.
- Jacques Barzun, "From Dawn to Decadence".