"This is the art of calculating the differences existing between each thing, by determining the relativeness of their respective proportions.
"Comparison acts on the mind automatically, as a rule.
"It is indispensable to the cultivation of common sense, for it furnishes the means of judging with full knowledge of all the circumstances.
"Analysis is an operation, which consists of separating each detail from the whole and of examining these details separately, without losing sight of their relationship to the central element.
"Analysis of the same object, while being scrupulously exact, can, however, differ materially in its application, according to the way that the object is related to this or that group of circumstances.
"There are, however, immutable things.
"For example: the letters of the alphabet, the elementary sounds, the colors etc., etc.
"It suffices to quote only these three elements; one can easily understand that the most elaborate manuscript is composed of only a definite number of letters always repeating themselves, whose juxtaposition forms phrases, then chapters, and finally the complete work.
"Music is composed only of seven sounds whose different combinations produce an infinite variety of melodies.
"Elementary colors are only three in number.