For Paracelsus, alchemy was not merely about the creation of gold, but was a medical and mystical philosophy that explained the functioning of the body (the transformation of food into flesh, blood and excrement) as well as the more general principles that revealed the mysteries of the earth. "Alchemy becomes so powerful and so beautiful in Paracelsus's hands," writes Ball, "because it is a part of a greater system: a magical vision of the universe distilled in the overheated alembic of a feverishly imaginative mind." Paracelsus saw the "great art of transformation" - alchemy - as the key to understanding man and nature. It was "a reflection of the natural art that makes a flower grow, that stores up metals in the earth, and brings wind and rain. By taking alchemy out of the smoky laboratory and setting it free in wild nature, Paracelsus stakes his claim to genius."