Although the ground-plan of Filarete’s ideal city of Sforzinda – two
regular interlocking squares enclosed by a circle – is one of the most
frequently reproduced quattrocento book illustrations, an adequate
interpretation has not yet been given.
A figure identical to Filarete’s plan is found in numerous older and
contemporary treatises that were accessible in the library of his patron,
Francesco Sforza. In these images the figure represents a geometrical
exposition of the cosmos, a diagram of universal order, the archetypal
idea of God the Creator; these resonances were purposefully invoked by
Filarete when he designed his ideal city. Abundant examples from
medieval and Renaissance Europe show that this figure was generally
understood as a depiction of the world, by artists and builders alike.
Further, in his text Filarete repeatedly emphasized macrocosmic
references, drawing a specific analogy between the founding of the city
and divine creation.
The implications of this argument are far reaching, and involve two
fundamental concerns of ‘Renaissance’ architects: their opinion as to the
nature of their profession and their own status, as well as what they, the
new, universally educated architects were claiming to achieve as the
effect of architecture. In other words, a full contextualization of
Filarete’s plan for Sforzinda reveals that, for the quattrocento architect,
a fundamental and lasting renewal of society was possible only through
the renewal of the built environment; this built renaissance is both the
first prerequisite and the continuing condition for all improvements, on
the human and societal level.