“Only within the 20th Century has biological thought been focused on ecology, or the relation of the living creature to its environment. Awareness of ecological relationships is — or should be — the basis of modern conservation programs, for it is useless to attempt to preserve a living species unless the kind of land or water it requires is also preserved. So delicately interwoven are the relationships that when we disturb one thread of the community fabric we alter it all — perhaps almost imperceptibly, perhaps so drastically that destruction follows.”

Source: Expanded Cinema, 1970, p. 346; The Artist as Ecologist http://www.screeningthepast.com/2011/11/the-artist-as-ecologist/; Partly cited in: Derek Owens. Composition and Sustainability: Teaching for a Threatened Generation. National Council of Teachers of English, 1 jan. 2001

"Unenchanted Evening", p. 40
Eight Little Piggies (1993)

Two in the Bush (1966)

Speech in the Commons during the debate which preceded the "Vote of No Addresses" (January 1648) as recorded in the diary of John Boys of Kent
Context: We declared our intentions to preserve monarchy, and they still are so, unless necessity enforce an alteration. It’s granted the king has broken his trust, yet you are fearful to declare you will make no further addresses... look on the people you represent, and break not your trust, and expose not the honest party of your kingdom, who have bled for you, and suffer not misery to fall upon them for want of courage and resolution in you, else the honest people may take such courses as nature dictates to them.

Wildlife Wars: My Fight to Save Africa's Natural Treasures (2001) with Virginia Morell

"Natural History: The Forgotten Science" [1938]; Published in Round River, Luna B. Leopold (ed.), Oxford University Press, 1966, p. 63-64.
1930s

House of Commons Debate (24 October 1969)

Reverence for Life (1969)
Context: At sunset of the third day, near the village of Igendja, we moved along an island set in the middle of the wide river. On a sandback to our left, four hippopotamuses and their young plodded along in our same direction. Just then, in my great tiredness and discouragement, the phrase "Reverence for Life" struck me like a flash. As far as I knew, it was a phrase I had never heard nor ever read. I realized at once that it carried within itself the solution to the problem that had been torturing me. Now I knew that a system of values which concerns itself only with our relationship to other people is incomplete and therefore lacking in power for good. Only by means of reverence for life can we establish a spiritual and humane relationship with both people and all living creatures within our reach. Only in this fashion can we avoid harming others, and, within the limits of our capacity, go to their aid whenever they need us.

The Sun My Heart (1996)
Context: Birds' songs express joy, beauty, and purity, and evoke in us vitality and love. So many beings in the universe love us unconditionally. The trees, the water, and the air don't ask anything of us; they just love us. Even though we need this kind of love, we continue to destroy them. By destroying the animals, the air, and the trees, we are destroying ourselves. We must learn to practice unconditional love for all beings so that the animals, the air, the trees, and the minerals can continue to be themselves.
Our ecology should be a deep ecology—not only deep, but universal. There is pollution in our consciousness. Television, films, and newspapers are forms of pollution for us and our children. They sow seeds of violence and anxiety in us and pollute our consciousness, just as we destroy our environment by farming with chemicals, clear-cutting the trees, and polluting the water. We need to protect the ecology of the Earth and the ecology of the mind, or this kind of violence and recklessness will spill over into even more areas of life.