Ladies and Gentlemen,—No word has played a more important part in the discussion of scientific and philosophical questions than the word Nature. Everyone thinks he knows the meaning of it. Yet how few have used it to express the same idea; indeed it has been employed to convey such a variety of impressions that John Stuart Mill asserts that it has been the "fruitful source" of the propagation of "false taste, false philosophy, false morality, and even bad law." Now, I propose in this lecture tha