Quotes from the book The Psychology of Perspective and Renaissance Art by Michael Kubovy.

"One should avoid thinking of perspective as a method that mimics, in some sense, what we see."

"Central projection is a somewhat more general geometric transformation than perspective."

"We might conclude that only disparate images seen by the two eyes can produce the sort of vivid experience of depth we are discussing. Such a conclusion would be premature, as we shall presently see. Indeed, on might say that the reason we do not see vivid depth in pictures (wether viewed with one eye or two) is not because they fail to fulfill the necessary conditions for such perception, but rather because pictures bear two kinds of incompatible information, information about the three-dimensional scene they represent, as well as information about their own two-dimensionality. It follows that if we could rid ourselves of the latter, the former should produce a vivid and compelling experience of depth, as stricking as stereopsis."

"Brunelleschi's use of a peephole in his first demonstration was instrumental in producing a compelling experience of depth for two reasons: First, it increased the effectiveness of the illusion by forcing the viewer to place his or her eye at the center of the projection of the perspective (thus making the picture a projective surrogate for the scene); second, it reduced the viewer's information regarding the flatness of the picture plane."

"And this implies that the Brunelleschi peephole can give rise to an illusion so strong that it could properly be called a delusion."

"Rosinski et al.'s experiment confirms Pirenne's hypothesis: If the subjects can see the picture plane, perspective is robust; if they cannot, perspective is not robust. In other words the availability of information regarding the location and the orientation of the plane is necessary and sufficient for the robustness of perspective."

"This observation suggests that although the standard claim about trompe l'oeil -- namely that it requires the representation of an object of shallow depth -- is true enough, it fails to do justice to the psychological complexity of the phenomenon. It is perhaps correct as a statement of a necessary condition for the occurence of the trompe l'oeil effect, but it leaves the question of the effect's sufficient conditions unmasked."

"Although we have shown that some distortions do take place in the perception of paintings that are viewed by moving observers, it is the robustness of perspective that emerges most clearly from our analysis. As we will see presently, it is this robustness that is probably the most important justification for not using Brunelleschi peepholes to view perspective paintings."

"The Alberti window differs from all others in that it functions properly only if it is not completely transparent: We must perceive the window in order to see the world." "Perhaps it is not the wide angle of the view per se, but rather local features of the depictions, that cause these pictures to look distorted."

"The visual system, so tolerant of variations in the representation of vertices of cubes, is completely intolerant of variations in the representation of spheres."

"So perspective, as it was practiced by the artists, was far from being an inflexible system. Because it was subordinated to perception and because different kind of objects were made to obey the laws of central projection to different extents, a unifying concept such as Alberti's window cannot do justice to the subtleties and complexities of Renaissance perspective."

"We cannot arbitrarily change the way we perceive optical information, nor can we arbitrarily change our motor responses to it, regardless of time or effort we might invest in doing so."

[c.f. experiments on people subjected to reverted vision]

"Even though perspective has a very sturdy geometric and perceptual foundation, which makes it, in some sense, the best method to represent space on a flat surface, the question of wether perspective is "true" is far less important than the inquiry about how perspective was put to use by Renaissance artists in an artistic context."