Aldo Leopold (1887–1948) is widely and rightly credited as being one of the founding fathers of the modern environmental movement. He was born in Burlington, Iowa in the United States, and discovered his passion for the natural world during boyhood wanderings in the wild country around the Mississippi River. After graduating from the Yale School of Forestry in 1909, he worked with the US Forest Service in Arizona and in New Mexico, where he was rapidly promoted, at just 24 years of age, to the position of Supervisor of the Carson National Forest.

He was very involved in developing proposals for the creation of the Gila Wilderness area in 1924 – the first of many wilderness areas that now exist throughout the United States. And in 1933 he published the first textbook in the science of wildlife management, a discipline that he founded virtually single-handedly. The book led on to his appointment at the University of Wisconsin as Professor of Game Management, a position he held until his untimely death.

Leopold was one of the first Nature writers in the West to propose that our ethical sensibilities should extend beyond the human realm to encompass the whole of Nature. His book A Sand County Almanac, published in 1949, is a classic in the field of ecological writing, and is one of the most readable, cogent and thought-provoking books on ecology ever written.

The Almanac conveys a powerful sense of connection with the natural world, which is deeply felt without being sentimental, well informed without being pedantic, and profoundly moral without engendering resentment or guilt in the reader. Its clear, intelligent style has assured its place both as a literary masterpiece and as a primer for developing the deep ecological consciousness that we so desperately need in our times. Even now, almost 65 years since its first publication, Leopold’s great work keeps on selling, with no prospect of its going out of print anytime soon.

Leopold’s underlying intention in the Almanac is nothing less than the major remediation of our Western human-centred worldview. He seeks to jettison our perspective which leads us to “abuse land because we regard it as a commodity belonging to us” in favour of seeing the land as “a community to which we belong” and which we must use with love and respect.

With great insight and simplicity, the Almanac describes the experiences in the natural world that led Leopold to develop his ‘Land Ethic’, the nub of which is that humans are just “plain members of the biotic community”. This ethic hinges on the insight that humankind is not the pinnacle of creation, and that it is a mistake to think of ourselves as the masters, stewards or controllers of Nature; ideas rejected by contemporary society that sees the more-than-human world as no more than a set of resources to be exploited for economic gain. In this sense Leopold’s views were advanced forerunners of the deep ecology perspective later developed by Arne Naess, the great Norwegian philosopher, whose key insight is that all life has intrinsic value, irrespective of its usefulness to humans.

If Leopold’s background had been in philosophy or the humanities one might perhaps not be unduly surprised by his success as one of the major sparks that ignited this deep ecological understanding in the West. But in fact he was a scientist, thoroughly trained in the hard-core mechanistic science of his day, which argued that Nature is no more than an inert machine that we humans have an absolute right to exploit without let or hindrance purely for our own benefit. What impresses me greatly about Leopold is that he somehow managed to shake off the shackles of this powerful mechanistic conditioning without any seeming conscious effort.

As a young Forest Service professional, Leopold had supported science-based efforts to exterminate wolves from the entire continental United States because he, like many others, thought that deer existed purely for the pleasure hunters derived in shooting them. Wolves therefore had to be eradicated so that there would be many more deer for hunters to kill. But following a close encounter with a wild wolf that Leopold himself had shot in the mountains of New Mexico, this view was completely swept away.

As he watched the “fierce green fire dying” in the old female wolf’s eyes he realised that there was “something new to me in those eyes – something known only to her and to the mountain ... I thought that because fewer wolves meant more deer ... no wolves would mean hunter’s paradise. But after seeing the green fire die, I sensed that neither the wolf nor the mountain agreed with such a view.”

Perhaps it is possible to understand the notion that a wolf disagreed with such a view. After all, the dying wolf was a fellow mammal with whom Leopold could feel a certain affinity. But how could a lifeless, inert mountain possibly agree or disagree with anything? What could Leopold have meant by that? What had he experienced at that pivotal moment? Clearly by ‘mountain’ he was referring to the wild ecosystem surrounding him as a living presence with its deer, its wolves and other animals, its clouds, soils and streams.

Leopold realised that this wide ecological reality had the power to communicate its palpable, sacred magnificence imbued with sentience and intelligence. He experienced the ecosystem as a great being, dignified and valuable in itself. It must have been a moment of tremendous liberation and expansion of consciousness, of joy and energy – a truly spiritual or religious experience. His narrow, manipulative wildlife manager’s mind fell away for good. The attitude that saw Nature as a dead machine vanished forever.

Leopold’s life took on an unerring new course after this powerful event. Thenceforth, he experienced the land and its living organisms as holders of a deeply important inward sentience. His scientific thinking became truly holistic. He thought that biodiversity conferred stability and integrity to ecological communities, making them more resistant to change and better able to recover from disturbance, a proposal denied by mainstream ecologists for many years but recently vindicated by scientists working with grassland communities in the field, with laboratory microcosm experiments and in the mathematical modelling of complex ecological communities.

Leopold’s message has major implications for our efforts to live harmoniously with the Earth, for nothing of lasting value will be achieved unless we begin to treat the wild world not as a slave to be subdued and exploited, but as a ‘person’ in the widest sense of the word. He believed “no important change in ethics was ever accomplished without an internal change in our intellectual emphasis, loyalties, affections, and convictions” and that hands-on experience of ecological restoration could help to bring about this radical inner reorientation, a task carried on to this day by the work of the Aldo Leopold Foundation on the land that he so passionately helped to restore, and on which he so tragically died whilst helping a neighbour to extinguish a grass fire.

Stephan Harding is a holistic scientist and is a co-founder of Schumacher College.