You see now--by taking first the great division of pre-Christian and
Christian arts, marked by the door of the Tower; and then the divisions
into four successive historical periods, marked by its angles--that
you have a perfect plan of human civilization. The first side is of the
nomad life, learning how to assert its supremacy over other wandering
creatures, herbs, and beasts. Then the second side is the fixed home
life, developing race and country; then the third side, the human
intercourse between stranger races; then the fourth side, the harmonious
arts of all who are gathered into the fold of Christ.
Now let us return to the first angle, and examine piece by piece with
care.