By considering the class of oxygen breathers and assigning an identity to them all (I presume all animals breathe oxygen), you are imagining a division among an undivided universe. A useful fiction. "Naming is the source of all particular things" -Buddha
Discussion
Sorry that was Laozi (Lao Tsu) who wrote "The unnamable is the eternally real. Naming is the origin of all particular things."
The Tao Te Ching 道德经 is as close as I get to religion/spirituality. It's just a perspective though, libertarian, stoic.
"Governing a large country is like frying a small fish. You spoil it with too much poking."