"Margulis and Lovelock were more than willing to mix science with philosophy and poetry, and they didn't mind controversy; in fact, I'd say they enjoyed and courted it. Gaia, subversively, blurs the boundaries between the scientific and the nonscientific. This may be one of its most valuable aspects, but is also a big reason that the scientific establishment has had so much trouble with it. Saying that "Earth is alive" is, of course, asking for it. The statement is both true and not true, profoundly insightful yet subject to infinite reinterpretation, and not a scientific statement that can be tested. Yet"