1. SCIENTIFIC STARTING POINT: Humans are part of a land pyramid, and human existence depends on the stability of that pyramid. 

2. PSYCHOLOGICAL HYPOTHESES: Self-interested "instincts" work to the detriment of the larger community. Social pressure is required to motivate people to limit their self-interested behavior. 

3. HOLISM: an anthropocentric (i.e., human-centered) ethic fails to locate humans within the context of the larger community. The land ethic "enlarges the boundaries of the community." An adequate ethic must view human behavior from the perspective of the total ecosystem. "A land ethic changes the role of Homo sapiens from conqueror of the land-community to plain member and citizen of it." 

4. VALUE hypothesis: Right action "implies respect for [our] fellow-members, and also respect for the community as such." "A thing is right when it tends to preserve the integrity [and] stability ... of the biotic community. It is wrong when it tends otherwise." Integrity & stability also demand bio-diversity.

ETHICAL corollary: Unregulated private property is inconsistent with land environmental health, so it is immoral. Another corollary: human population density is inconsistent with land environmental health, so it is immoral. 

Arguments that stress the ECONOMIC value of conservation end up falsifying the scientific truth. Reason: identification of the economic advantages of specific species or particular types of land & related biotic communities always require us to pull some elements of ecosystems out of context. Focus on economics always ignores the proper holism. 

Symptoms that we have failed to maintain the integrity & stability of the land: Pests, Disease, Extinction, Erosion, Pollution, Non-native Species.

POPULATION DENSITY always creates imbalance. Therefore population density is our most immediate evidence that we are acting wrongly in relation to our environment.

J. BAIRD CALLICOTT defends Leopold against wrong interpretations (in James White textbook, 8th ed)

Leopold's land ethic is NOT a defense of vegetarianism. It is NOT a defense of animal rights.

STANDARD arguments for vegetarianism usually emphasize the suffering of animals or they emphasize health benefits.

STANDARD arguments for animal rights usually emphasize the sentience & self-awareness of animals, and their capacity to suffer.

These standard arguments seem radical because they attack the ANTHROPOCENTRIC (i.e., human-centered) assumption that all and only humans (members of our species) are of moral concern. (Callicott calls this old assumption "ethical humanism.")

But they are NOT radical. They are still ATOMISTIC (they break the problem down into basic units and then worry about the moral consequences of interactions among those units). Traditional ethics ("ethical humanism") assumes that the basic unit is the individual human being.

HEALTH defenses of vegetarianism remain completely atomistic.

ANIMAL RIGHTS arguments, and vegetarianism based on animal rights, are both attempts to ANTHROPOMORPHIZE animals that are highly similar to us. So the approach remains ATOMISTIC (individual animals are the basic unit of analysis) and it is still anthropocentric (we start with humans at the center of the analysis, and then extend rights out to animals that are sufficiently like us).

Leopold's land ethic is NOT atomistic. The basic unit of the analysis is the ecosystem or biotic community (including the soil, air, water). Humans count for no more than any other part of the complex land pyramid on which they perch. So the land ethic is not anthropocentric, and it does not anthropomorphize. IT IS GENUINELY RADICAL.