Vitruvius

Beauty is produced by the pleasing appearance and good taste of the whole, and by the dimensions of all the parts being duly proportioned to each other.

Nothing requires the architect's care more than the due proportions of buildings.

For an object under the eye will appear very different from the same object placed above it; in an inclosed space, very different from the same in an open space.

Architecture is a science arising out of many other sciences, and adorned with much and varied learning; by the help of which a judgment is formed of those works which are the result of other arts.

If nature has composed the human body so that in its proportions the seperate individual elements answer to the total form, then the Ancients seem to have had reason to decide that bringing their creations to full completion likewise required a correspondence bewteen the measure of individual elements and the appearance of the work as a whole.