A high state of civilisation is in a large measure to be traced to climate and soil. The sequence is somewhat as follows:—
Mountains collect rain.
Rain fills the rivers.
Rivers make rich alluvial plains.
Agriculture follows; and food is produced.
Abundant food maintains a large population.
The population works to supply its various wants; such as roads, railways, ships, houses, machinery, etc. Then follows exchange with other countries. They send us what they can best produce, and we send them what we can best and most easily produce, and so both parties gain.
Thus towns spring up. Education, refinement, learning, and the higher arts follow from the active life of towns, where more brain-work is required, and the standard of life is higher.
And thus we may, in imagination, follow step by step the various stages by which the highest phases of civilisation are brought to pass, beginning at the mountains and ending with human beings of the highest type,—the philosopher, artist, poet, or statesman, not omitting the gentler sex, who are often said to rule the world.
The following lines of Milton possess, in the light of these facts, a deeper meaning than the poet probably intended to convey:—