“A fish swims in the ocean, and no matter how far it swims there is no end to the water. A bird flies in the sky, and no matter how far it flies, there is no end to the air. However, the fish and the bird have never left their elements. When their activity is large their field is large. When their need is small their field is small. Thus, each of them totally covers its full range, and each of them totally experiences its realm."

Dogen, Genjo Koan