I do not underrate the yearning for mechanical and formal tests. They are possible and useful in zones upon the legal sphere. The pain of choosing is the pain of marking off such zones from others. It is a pain we must endure, for uniformity of method will carry us upon the rocks. The curse of this fluidity, of an ever shifting approximation, is one the law must bear, or other curses yet more dreadful will be invited in exchange.
Pages 67 – 68. - The Growth of the Law (1924)