The precise identification of the causes of the environmental crisis is neither simple nor straightforward. A number of environmental and ethical treatises tend to rely on a single explanatory variable, though the variable differs from author to author. The ecologist Paul Ehrlich in his book The Population Explosion proposes over-population as the fundamental cause which needs addressing if the crisis is to be averted. The environmental economists Dennis and Donella Meadows in the influential Club of Rome Report The Limits to Growth identify the economics of growth as the central cause of environmental over-exploitation. Robin Attfield in his seminal study The Ethics of Environmental Concern identifies the pursuit of progress as the central feature of the modern world-view which has given rise to the environmental crisis. Theodore Roszak, Edward Goldsmith and Rupert Sheldrake argue that the modern scientific method is the source of the distorted relationship between humanity and nature which has produced the crisis. Some propose that the environmental crisis is basically a problem of changing cultural attitudes to the non-human world, or of the social construction of nature. Thus Lynn White in a famous article blames it on the Christian doctrine of creation, and in particular the Genesis command to dominate and subdue the earth. Others blame it on ‘Cartesian dualism’, the disjunction between rationality and embodiment, nature and culture which is said to have originated in the philosophy of the Enlightenment. Ecofeminists such as Mary Daly or Rosemary Radford Ruether believe the problem of humanity and nature originates in gender construction and patriarchy: the oppression and abuse of nature through technology are seen as symptomatic of the male tendency to dominate and control.