Environmental Ethics

The last man and the birth of the field

Environmental ethics began with a thought experiment. In a 1973 paper, Australian philosopher Richard Routley (later Sylvan) asked us to imagine the last man on a dying Earth, knowing he is the last, setting out to destroy every living thing he can find — burning forests, poisoning rivers — purely for sport. No human will ever be harmed; there are none left.

Most readers feel the last man does something wrong. But standard Western ethics — Kantian, utilitarian, contractualist — struggles to explain why, since each grounds moral status in something humans have: rationality, sentience, the capacity to contract. Either our intuition is mistaken, or moral status reaches further than mainstream ethics supposed. Environmental ethics took the second branch.

Aldo Leopold and the land ethic

The seed had been planted twenty-four years earlier. Aldo Leopold, a U.S. Forest Service ranger turned ecologist, watched an old wolf die after he shot her on a Southwestern hillside in the 1920s. "I was young then, and full of trigger-itch," he later wrote. "I thought that because fewer wolves meant more deer, that no wolves would mean hunters' paradise. But after seeing the green fire die in her eyes, I sensed that neither the wolf nor the mountain agreed with such a view."

The book closes with the essay "The Land Ethic," proposing that human ethics began regulating relations between individuals, expanded to individual and society, and must now expand again "to include soils, waters, plants, and animals, or collectively: the land." Leopold's maxim — "A thing is right when it tends to preserve the integrity, stability, and beauty of the biotic community. It is wrong when it tends otherwise." — became the founding principle of holistic environmental ethics.

Three positions on moral standing

	Anthropocentric	Biocentric (individualist)	Ecocentric (holist)
Locus of value	Humans only	Each living organism	Species, ecosystems, biosphere
Why nature matters	Human use, beauty, science	Each life pursues its own good	Wholes have integrity / health
Canonical author	John Passmore (1974)	Paul Taylor (1986)	Aldo Leopold (1949)
Last-man verdict	Hard to condemn	Wrong: kills beings with goods	Wrong: destroys biotic community
Trade-off it accepts	Can deprioritise distant species	Cannot endorse predation, culls	Can sacrifice individuals for wholes
Easiest to operationalise	Yes — in standard cost-benefit	Hard — too many bearers	Moderate — via ecosystem health
Famous critic	Routley's "last man"	Callicott (too individualist)	Tom Regan ("environmental fascism")

Deep ecology

The most influential extension came from Arne Naess, a Norwegian philosopher and mountaineer. In 1973 Naess distinguished "shallow" ecology — preventing pollution for human benefit — from "deep" ecology, which calls into question human supremacy itself.

In 1984 Naess and George Sessions published the eight-point Deep Ecology Platform. Its first plank: "The well-being and flourishing of human and non-human life on Earth have value in themselves. These values are independent of the usefulness of the non-human world for human purposes." Subsequent points defend biological diversity, demand a substantial decrease in human population, and call for an "ideological change" away from ever-rising standards of living.

Deep ecology has been criticised as mystical and politically naïve (the population claim drew the sharpest fire). But after Naess, environmental ethics could no longer be framed as utilitarianism with a green tint.

Key philosophers and their contributions

• Aldo Leopold, A Sand County Almanac (1949). The land ethic extends moral community to soils, waters, plants, and animals; right action preserves the integrity, stability, and beauty of the biotic community.
• Lynn White Jr., "The Historical Roots of Our Ecologic Crisis" (1967). Argues the dominant Western tradition — Genesis 1:28's "have dominion" — bears moral responsibility for the ecological crisis.
• Richard Routley (Sylvan), "Is There a Need for a New, an Environmental Ethic?" (1973). The "last man" argument that pushed mainstream philosophy to recognise the field.
• Arne Naess (1973). Coined "deep ecology"; launched the most ambitious anti-anthropocentric programme.
• Holmes Rolston III, Environmental Ethics (1988). Most systematic theorist of intrinsic value in nature; values exist in degrees from organisms up through species and ecosystems.
• Paul Taylor, Respect for Nature (1986). Biocentric individualism: every living thing is a "teleological centre of life" pursuing its own good.
• J. Baird Callicott, In Defense of the Land Ethic (1989). The leading philosophical defender of Leopold's position.
• Val Plumwood, Feminism and the Mastery of Nature (1993). Ecofeminist analysis linking domination of nature to other "logics of mastery."

Worked example: a wolf reintroduction programme

In 1995, after a 70-year absence, grey wolves were reintroduced to Yellowstone National Park. The decision is a useful stress test for environmental theories.

Anthropocentric. Wolves attract tourist revenue and reduce overgrazing, improving fishing streams. Net human benefit positive — proceed. Ranchers lose livestock; compensation funds required. The decision turns on cost-benefit accounting and could flip if tourism declined.

Biocentric individualist (Taylor). Each wolf has a good of its own and is owed respect. So is each elk and each cottonwood seedling. Reintroduction multiplies wolves but also multiplies elk deaths. The theory struggles: it cannot assign weights to balance one organism's good against another's.

Ecocentric (Leopold/Callicott). Yellowstone had lost its apex predator. Reintroduction restores ecological integrity — vegetation recovers, beaver populations rise, songbird diversity climbs. Wolves' hunting is the mechanism by which the whole returns to health: clearly endorsed.

Deep ecology. Endorses for the same reasons, plus a duty to undo past violations of biological diversity wherever feasible.

The example shows why ecocentric ethics dominates conservation policy: it gives clear verdicts where individualist views stall.

Counterarguments and replies

Objection: "environmental fascism." Tom Regan's notorious charge against Leopold: if the biotic community's integrity is supreme, the theory could endorse culling humans who disturb ecosystems. Reply (Callicott): the land ethic adds an ecological layer atop human ethics; prior obligations are not erased.

Objection: ecosystems do not have interests. Only individuals can strictly be benefited or harmed. Reply: ecosystems have measurable functional health — energy throughput, diversity, resilience. Whether you call that an "interest" is semantic; the underlying property is real.

Objection: intrinsic value is metaphysically suspicious. Where does it reside if there are no valuers? Reply (Rolston): nature is value-creating, not just value-receiving — evolution produces creatures with goods of their own. Even deflationary readings (Norton) note that anthropocentric and non-anthropocentric ethics often converge in practice.

Objection: deep ecology is politically dangerous. Population-reduction language has been misused. Reply (Naess): deep ecology is committed to social justice and non-coercive means; misuses are real but not entailed.

Variants and adjacent traditions

• Ecofeminism (Plumwood, Karen Warren). Diagnoses the domination of nature as continuous with the domination of women.
• Social ecology (Murray Bookchin). Locates environmental crisis in hierarchical social structures rather than human nature.
• Environmental pragmatism (Bryan Norton). Sets aside the intrinsic-value debate; focuses on cross-worldview policy consensus.
• Rights of nature (Christopher Stone, 1972). Rivers and ecosystems as legal persons; adopted in Ecuador (2008) and New Zealand (2017).
• Climate ethics (Gardiner, Shue). Climate as the defining intergenerational, global moral problem.

Common confusions

• Environmentalism is not environmental ethics. The first is a movement; the second is the philosophical investigation that grounds it.
• Anthropocentric does not mean selfish. A perfectly altruistic human-centred ethic still counts as anthropocentric.
• Intrinsic value does not mean felt value. Non-sentient ecosystems can bear intrinsic value on most theories.
• Deep ecology is not a religion. Naess insisted it is a normative philosophy with empirical commitments.
• Leopold did not oppose hunting. He was a lifelong hunter; his ethic regulates hunting, it does not abolish it.