From "Flatland" by Edwin Abbott AbbottYou, who are blessed with shade as well as light, you, who are gifted with two eyes, endowed with a knowledge of perspective, and charmed with the enjoyment of various colours, you, who can actually SEE an angle, and contemplate the complete circumference of a Circle in the happy region of the Three Dimensions-- how shall I make it clear to you the extreme difficulty which we in Flatland experience in recognizing one another's configuration?
