Rothenberg's effort is special because he utilizes perspectives from philosophy, psychology, art, and linguistics in considering the creative process. There is a good index and useful footnotes. For example, Darwin is known to have carefully read Malthus while formulating his theory, but Rothenberg finds Darwin accepted Malthus' point rather than rejected it. "He accepted and understood Malthus's point that the struggle for existence could lead to devastating destruction of the species but thought that it also led to adaptive selection." This is part of a lengthy consideration of janusian thinking.