I think Brad’s observation that Tolkien really hated what industrial technology could do to people and the environment is a key to understanding orcs. When you take something wise, beautiful, and in balance – like an elf – and subject it to technology what you get is something which has been stunted, twisted, and degenerated – an orc. Orcs are the animal version of what Saruman is doing to Fangorn forest. In this way they serve as a warning about what could happen to humans as well.
