Go out in the winter on a calm, frosty day into the field, or into the woods, and look about you and listen: all around you is snow, the rivers are frozen, dry grass blades stick out of the grass, the trees are bare,—nothing is moving. Look in the summer: the rivers are running and rippling, in every puddle the frogs croak and plunge in; the birds fly from place to place, and whistle, and sing; the flies and the gnats whirl around and buzz; the trees and the grass grow and wave to and fro. Freeze a pot with water, and it will become as hard as a rock. Put the frozen pot on the fire: the ice will begin to break, and melt, and move; the water will begin to stir, and bubbles will rise; then, when it begins to boil, it whirls about and makes a noise. The same happens in the world from the heat. Without heat everything is dead; with the heat everything moves and lives. If there is little heat, there is little motion; with more heat, there is more motion; with much...