Quotes from the book Perspective as Symbolic Form by Erwin Panofsky.
"Exact perspectival construction is a systematic abstraction from the
structure of this psychophysiological space. For it is not only the effect of
perspectival construction, but indeed its intended purpose, to realize in the
representation of space precisely that homogeneity and boundlessness
foreign to the direct experience of that space. In a sense, perspective
transforms psychophysiological space into mathematical space."
"Perspectival construction ignores the crucial circumstance that this retinal
image -- entirely apart from its subsequent psychological "interpretation",
and even apart from the fact that the eye moves -- is a projection not on a
flat but on a concave surface. Thus already on this lowest, still
prepsychological level of facts there is a fundamental discrepency between
"reality" and its construction."
"One must always remember that contemporary or near-contemporary reports can
of course only measure the "naturalism" of an artistic representation against
what has already been achieved, against what is conceivable."