Published online by Cambridge University Press: 20 November 2018
Renaissance humanism was not, and probably could never have been, permanently confined to the restricted company that had once created it. Even its most esoteric branches — Neoplatonism, magic, cabala, alchemy—had their practical side, for they had been conceived and continued to operate in a world of practical needs. By the first two decades of the early sixteenth century, fundamental concepts of Neoplatonism, though they may have retained their esoteric charm for self-conscious cognoscenti, had also become common coin, the imagery in which merchants, professionals, and technicians couched their own philosophical yearnings. At the same time, humanistic patterns of thought had come to govern actions in the political and financial sphere no less than they governed the progress of letters and art.
The following paper was first delivered in a much different form at the annual meeting of the Renaissance Society of America, Tempe, Arizona, March 1987. My thanks to Bill Engel, Maureen Pelta, Cynthia Pyle, Nicholas Adams, and Lauro Martines for suggestions on that original paper, and to Thomas Howe for patiently overseeing its transformation to the present version. Three anonymous readers contributed choice phrases, here gratefully appropriated, in addition to sage advice. Thanks are due as well to the Biblioteca Apostolica Vaticana, the Archivio di Stato di Siena, the Archivio di Stato di Roma, and the Newberry Library, Chicago, for their unfailing help.