>"[Saruman] is plotting to become a Power. He has a mind of metal and wheels; and he does not care for growing things, except as far as they serve him for the moment" (Tolkien)
The phrase "a mind of metal and wheels" has always stuck with me as a pejorative; this is in contrast with modern phrases like, "He's a machine!" said in a positive way. The mind of metal and wheels is transactional, utilitarian, devoid of sentiment. It would be more like a natural process than a person, if not for ego.