Man and beast did not always bleed. Once, there was no injury or fear of death, although there was deprivation.
Two brothers in this time walked through a forest. One was known as Industry, the other as Foresight. Foresight remarked to his brother, "This is a fine forest, but soon there will be many people, and we will not be able to live on its fruits." Industry replied, "Then we will expand beyond the forest, and find new sources of food." And they walked on.
They left the forest, and walked along a plain. Foresight remarked, "We will have no shelter here, and less food." Industry replied, "We will bring the forest with us for shelter, and grind the grasses into food." And they walked on.
They came to the ocean, and walked along the beach. Foresight remarked, "Eventually, we will run out of trees, and land. What then, brother?" Industry looked around. "We will build from the clay, and from stone. We will build up. And perhaps we will find a way to cross the ocean." Then they stripped, and swam in the ocean.
After swimming, they came upon an island. "There may be another land beyond the ocean, brother, but eventually we will reach all lands. And the faster we expand, the harder it will be to keep us fed and sheltered and clothed." Foresight looked at his brother. "Do you have an answer?" Industry looked troubled. "Forests will regrow, plants will regrow, but land will not, nor will stone. I have no answer to your problem." Foresight nodded. "I do. Trees end, when they are cut down. The day ends, and so does the night. So too should the lives of man and beast." Industry thought on this. "I have a way to do this. A vital fluid that one can lose. But it can only come at a cost." They paused a great while.
"I will pay the cost. Give man an ending, brother." And so, one brother killed the other, and turned his body into the first blood, which he then set flowing in all beasts and men, so that mercy was an option.