In all matters but particularly in architecture ...that which is signified is the subject of which we may be speaking and that which gives significan… - Vitruvius

Quoth he [ Alexander ] "...as a newborn babe cannot be nourished without the nurse's milk, nor conducted to the approaches that lead to growth in life, so a city cannot thrive without fields and the fruits thereof pouring into its walls."

With the present importance of the city [of Rome] and the unlimited numbers of its population, it is necessary to increase the number of dwelling-places indefinitely. Consequently, as the ground floors could not admit of so great a number living in the city, the nature of the case has made it necessary to find relief by making the buildings high. In these tall piles reared with piers of stone, walls of burnt brick, and partitions of rubble work, and provided with floor after floor, the upper stories can be partitioned off into rooms to very great advantage. The accommodations within the city walls being thus multiplied as a result of the many floors high in the air, the Roman people easily find excellent places in which to live.

Towns should be laid out not as an exact square nor with salient angles, but in circular form, to give a view of the enemy from many points. Defense is difficult where there are salient angles because the angle protects the enemy rather than the inhabitants.