in Thoreau’s Journal:

It would be worth the while to tell why a swamp pleases us, what kinds please us, also what weather, etc., etc., – analyze our impressions. Why the moaning of the storm gives me pleasure. Methinks it is because it puts to rout the trivialness of our fair-weather life and gives it at least a tragic interest. The sound has the effect of a pleasing challenge, to call forth our energy to resist the invaders of our life’s territory. It is musical and thrilling, as the sound of an enemy’s bugle. Our spirits revive like lichens in the storm.

There is something worth living for when we are resisted, threatened. As at the last day we might be thrilled with the prospect of the grandeur of our destiny, so in these first days our destiny appears grander. What would the days, what would our life, be worth, if some nights were not dark as pitch, – of darkness tangible or that you can cut with a knife? How else could the light in the mind shine? How should we be conscious of the light of reason? If it were not for physical cold, how should we have discovered the warmth of the affections? I sometimes feel that I need to sit in a far-away cave through a three weeks’ storm, cold and wet, to give a tone to my system. The spring has its windy March to usher it in, with many soaking rains reaching into April. Methinks I would share every creature’s suffering for the sake of its experience and joy.