If a potato can produce vitamin C, why can't we? Within the animal kingdom only humans and guinea pigs are unable to synthesize vitamin C in their own bodies. Why us and guinea pigs? No point asking. Nobody knows.
Human beings are a part of the animal kingdom, not apart from it. The separation of "us" and "them" creates a false picture and is responsible for much suffering. It is part of the in-group/out-group mentality that leads to human oppression of the weak by the strong as in ethic, religious, political, and social conflicts.
ZOOLOGY, n. The science and history of the animal kingdom, including its king, the House Fly ("Musca maledicta"). The father of Zoology was Aristotle, as is universally conceded, but the name of its mother has not come down to us.
Chimpanzees, more than any other living creature, have helped us to understand that there is no sharp line between humans and the rest of the animal kingdom. It's a very blurry line, and it's getting more blurry all the time.
A river is the most human and companionable of all inanimate things. It has a life, a character, a voice of its own; and it is as full of good fellowship as a sugar maple is of sap. It can talk in various tones, loud or low, and of many subjects grave and gay.... For real company and friendship there is nothing, outside of the animal kingdom, that is comparable to a river.
The ability to see yourself as a temporary expression of intention and to see yourself in all of humanity is a characteristic of the holy relationship. It's the ability to celebrate and honor in all others, the place where we're all one. ...establish a holy relationship with your Source, the world community, your neighbors, acquaintances, family, the animal kingdom, our planet, and yourself.
The animal kingdom exhibits a series of mental developments which may be regarded as antecedents to the mental development of man, for the mental life of animals shows itself to be throughout, in its elements and in the general laws governing the combination of the elements, the same as the mental life of man.