Long before people began making compost piles composting was happening. Compost is the result of the decomposition of organic materials. Everything that came from the earth goes back to the earth. That is the natural rule that has kept the earth clean for as long as it has hosted life. Without the agents of decomposition the earth would be overrun with plant and animal wastes. Imagine if every leaf that fell to the ground never changed, if every bit of manure that hit the ground, and every creature that perished simply stayed where it fell. Throughout the ages, whether it be rock, tree, or crude oil, everything decomposes.