It is now almost a prerequisite of any dispute among environmentalists to recall a judgment offered by the literary critic Raymond Williams – that ‘nature’ is perhaps the most complex word in the English language. Attempts to unravel its meaning are fraught with challenge. Does it signify just the living elements of the biosphere, or does it include inanimate parts, such as mountains and rivers? The extreme heat of the Sun at its core makes it the place least hospitable to life – yet it is equally the source of the whole process.