Analysis of Earth's Secret

Not solitarily in fields we find
Earth's secret open, though one page is there;
Her plainest, such as children spell, and share
With bird and beast; raised letters for the blind.
Not where the troubled passions toss the mind,
In turbid cities, can the key be bare.
It hangs for those who hither thither fare,
Close interthreading nature with our kind.
They, hearing History speak, of what men were,
And have become, are wise. The gain is great
In vision and solidity; it lives.
Yet at a thought of life apart from her,
Solidity and vision lose their state,
For Earth, that gives the milk, the spirit gives.