The idea of a human nature that is fixed, stable or essential has been disputed on the biological (Darwin) and philosophical (Nietzsche) grounds. The latter I have some sympathy with, the former I find it a little harder to accept – particularly in its John Harris manifestation. I am not entirely sure what Žižek is getting at when he says further alienation from our roots in nature is required rather than a return to nature to deal with the ‘ecological crisis’.