Is there any knowledge in the world which is so certain that no reasonable man could doubt it? ..... It follows that if several people are looking at the table at the same moment, no two of them will see exactly the same distribution of colors, because no two can see it from the same point of view, and any change in the point of view makes some change in the way the light is reflected.
――四天王寺国際仏教大学――2003年