In 1867, George Campbell, Duke of Argyll, had published The Reign of Law, a book that Darwin found deeply annoying. A supporter of Richard Owen, Campbell argued that while evolution (or "Development") might be observable in the fossil record, it was merely evidence of God's purpose. God, for example, would cause horses and oxen to evolve in time to meet human needs. The brightly colored plumage of birds, Campbell went on, were simply God's decorations of nature for humanity's enjoyment.