Vogel argument is that the word "nature" has two completely different meanings, and both of them collapse under scrutiny when you actually try to use them for environmentalism.

Meaning 1 is nature as in everything, the whole physical world, humans included. Drawing on John Stuart Mill, Vogel describes it as:

"the totality of the physical world subject to the ordinary forces described by physics and chemistry and evolutionary biology, and in this sense human beings, like every other species, are surely natural."

So in this sense, humans are natural. Everything we do is natural. A factory, a highway, a nuclear plant, all natural. The opposite of natural here would be supernatural, which is basically an empty category.

Meaning 2 is nature as in the non-human world, what McKibben means when he says nature has "ended" because human activity has touched every corner of the earth. The opposite here isn't supernatural, it's artificial. This is what people mean when they talk about natural foods or natural fibers. Vogel quotes McKibben directly on what makes this definition tick:

"We have deprived nature of its independence, and that is fatal to its meaning. Nature's independence is its meaning; without it there is nothing but us."

Now here's where it gets really interesting. Vogel shows that neither definition actually does what environmentalism needs it to do.

With meaning 1, you simply cannot harm nature, because everything is already nature by definition:

"Nuclear power plants and toxic waste dumps are no less natural than beaver dams or spider webs; the atmospheric consequences of global warming and chlorofluorocarbon use are no less natural than those of photosynthesis or respiration. If nature simply means the physical world, then nature is really in no danger."

With meaning 2, the destruction of nature by humans isn't really a discovery, it's just true by definition, before you even look at the world:

"Human actions will be unnatural not because of what they do to the world but merely because they are actions performed by humans."

And you can't build a serious ethical critique on something that's analytically guaranteed to be true no matter what choices anyone makes. It's like condemning beavers for destroying bature, the world independent of beaver activity. It would be technically true and completely pointless.

Then Vogel goes even deeper. He argues that meaning 2 secretly depends on an old Cartesian mind/body dualism, the idea that human minds somehow lift us outside the natural order, even though our bodies are fully in it. And this leads to a genuinely uncomfortable conclusion:

"Humans stand in an absolutely unique and distinctive relation to nature, according to this view: alone of all the species in the world, their acts have the special ability to move something out of the natural realm entirely, because they possess qualities of reason that themselves transcend nature."

Which means environmentalism, in trying to push back against anthropocentrism, has actually been quietly reproducing it all along, just with the signs flipped. Humans are still the exceptional species, still cosmically set apart from everything else. Just villainous this time instead of glorious.

His conclusion is that the concept of nature might simply be too tangled, too ambiguous, and too philosophically compromised to hold up an environmental philosophy. Not a comfortable place to land, but after following his argument it's genuinely hard to disagree.

Source : https://ebrary.net/79263/computer_science/_nature_place_environmental_philosophy