First Sentence

"THE NOTION of proportion is, in logic as well as in Aesthetics, one of the most elementary, most important, and most difficult to sort out with precision; it is either confused with the notion of ratio, which comes logically before it, or (especially when talking of proportions in the plural) with the notion of a chain of characteristics ratios linked together by a modulus, a common sub-multiple; we have then the more complex concept which the Greeks and Vitruvius called "Symmetria," and the Renaissance architects, "Commodulatio.""