in Thoreau’s Journal:

No wonder we feel the spring influences. There is a motion in the very ground under our feet. Each rill is peopled with new life rushing up it.

If a man does not revive with nature in the spring, how shall he revive when a white-collared priest prays for him?

…..We too are out, obeying the same law with all nature– Not less important are the observers of the birds than the birds themselves.