From the point of view of absolute truth a cube or a circle are invariable geometrical figures, rigorously defined by certain formulas. From the point of view of the impression they make on our eye these geometrical figures may assume very varied shapes. By perspective the cube may be transformed into a pyramid or a square, the circle into an ellipse or a straight line. Moreover, the consideration of these fictitious shapes is far more important than that of the real shapes, for it is they and they alone that we see and that can be reproduced by photography or in pictures. In certain cases there is more truth in the unreal than in the real.
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