Meyer Schapiro, from "Nature of Abstract Art" 1937:
"In the Renaissance the development of linear perspective was intimately tied to the exploration of the world and the renewal of physical and geographical science. Just as for the aggressive members of the burgher class a realistic knowledge of the geographical world and communications entailed the ordering of spatial connections in a reliable system, so the artists strove to realize in their own imaginative field, even within the limits of a traditional religious content, the most appropriate and stimulating forms of spatial order, with the extensiveness, traversability and regulation valued by their class. And similarly, as this same burgher class, emerging from a Christian feudal society, began to assert the priority of sensual and natural to ascetic and supernatural goods, and idealized the human body as the real locus of values-enjoying images of the powerful or beautiful nude human being as the real man or woman, without sign of rank or submission to authority--so the artists derived from this valuation of the human being artistic ideals of energy and massiveness of form which they embodied in robust, active or potentially active, human figures. And even the canons of proportion, which seem to submit the human form to a mysticism of number, create purely secular standards of perfection; for through these canons the norms of humanity become physical and measurable, therefore at the same time sensual and intellectual, in contrast to the older medieval disjunction of
body and mind."
