Do action in harmony with nature.
After two weeks of drought, it rains. The snails sail forth en masse in the darkness, it is mating time. In my ignorance I fail to see the snails, three die before I cast my torch-light upon the silent population on the ground, but not before a fourth dies on the grass that my torch-light did not see. Thus the light of wisdom shines forth in my mind as my torch picks up the invisible living creatures before me, that after rain in the darkness snails will seek to mate, and I must with greater care place my feet.
Earlier in the day I walked past a dead pigeon, the latest casualty of billions of animals that die from collisions with vehicles on the roads. It takes hundreds to thousands of years for animals and plants to adapt to changing environments, changes that are often slow in coming, but they are unable to adapt to the fast changes of humanity, the motorcar invented a hundred years before, followed by car parking and roads that cover former living grounds of nature in tarmac.
Animals such as the snail and pigeon only understand a part of their world, one born of instinct, unfamiliar to the ways of humanity. It is for humans with their greater understanding of the world we share with plants and animals to adapt and accommodate the living things around us, for they are unable to, and they suffer from our indifferent attitudes. It is for me to place my feet carefully in the dark after rain, for the snail has no ability or understanding of the dangers of my feet to them. I define sustainability as action in harmony with nature, and so I must harmonise my actions with the snail to tread with care so that snails may live.