in Thoreau’s Journal:
It is vain to try to write unless you feel strong in the knees.
Any book of great authority and genius seems to our imagination to permeate and pervade all space. Its spirit, like a more subtle ether, sweeps along with the prevailing winds of the country. Its influence conveys a new gloss to the meadows and the depths of the wood, and bathes the huckleberries on the hills, as sometimes a new influence in the sky washes in waves over the fields and seems to break on some invisible beach in the air. All things confirm it. It spends the mornings and the evenings.