The mind that thought of light, heavy, grey, yellow, still, swift, also conceived of magic that would make heavy things light and able to fly, turn grey lead into yellow gold, and the still rock into a swift water. If it could do the one, it could do the other; it inevitably did both. When we can take green from grass, blue from heaven, and red from blood, we have already an enchanter's power.
J. R. R. Tolkien