While understandable as a philosophical construct, Vitruvius’ description inevitably distorts the human shape, since actual human variations would deform the perfect square and circle into an ellipse, rectangle, or non-pure geometry. In Leonardo’s sophisticated sketch, there is no distortion of the human form; the drawing suggests that the system works just as Vitruvius’ text describes. However, this is an illusion because the drawing, unmoored from any real human body, is merely conceptual.
This is the underlying irony of the Vitruvian formula: despite being profoundly anthropocentric, Interior design the system is detached from actual human bodies, even when direct measurements are called for, as Alberti did in his 1464 treatise De Statua. Alberti wrote that human measurements could be used to find the “highest beauty scattered, as if in calculated portions among many bodies.”35 As Rudolf Wittkower summarizes, taking those dimensions from “a number of bodies considered to be the most beautiful” would determine the ideal human form, eliminating the “imperfections in natural objects” even while “combining their most typical parts.” For most orthodox humanists during the Renaissance, this ideal “seemed to reveal a deep and fundamental truth about man and the world.”36 This interpretation of the body was the source from which all art, architecture, and design could originate.
These beliefs held currency until the mid-eighteenth century, when rationalist thinking began to challenge the unquestioned faith in classical rules of proportion. In 1757, Edmund Burke, in a section of his Philosophical Enquiry into the Origin of our Ideas of the Sublime and Beautiful titled “Proportion not the Cause of Beauty in the Human Species,” challenged the belief that proportion alone was the source of human beauty. Burke found the long-held proposition of a direct correlation between human proportions and built forms particularly troubling:
I know that it has been said long since, and echoed backward and forward from one writer to another a thousand times, that the proportions of building have been taken from those of the human body. To make this forced analogy complete, they represent a man with his arms raised and extended at full length, and then describe a sort of square, as it is formed by passing lines along the extremities of this strange figure. But it appears very clearly to me, that the human figure never supplied the architect with any of his ideas. For, in the first place, men are very rarely seen in this strained posture; it is not natural to them; neither is it at all becoming. Secondly, the view of the human figure so disposed, does not naturally suggest the idea of a square, but rather of a cross; as that large space between the arms and the ground must be filled with something before it can make anybody think of a square.37