The lower animals are our brethren. I include among them the lion and the tiger. We do not know how to live with these carnivorous beasts and poisonous reptiles because of our ignorance.
If the basic human nature was aggressive, we would have been born with animal claws & huge teeth -- but ours are very short, very pretty, very weak! That means we are not well equipped to be aggressive beings. Even the size of our mouth is very small. So I think the basic nature of human beings should be gentle.
I usually say the aim of life is to be happy. Our existence is based on hope. Our life is rooted in the opportunity to be happy, not necessarily wealthy, but happy within our own minds. If we only indulge in sensory pleasure, we'll be little different from animals. In fact, we have this marvellous brain and intelligence; we must learn to use it.
What strength belongs to every plant and animal in nature. The tree or the brook has no duplicity, no pretentiousness, no show. It is, with all its might and main, what it is, and makes one and the same impression and effect at all times. All the thoughts of a turtle are turtle's, and of a rabbit, rabbit's. But a man is broken and dissipated by the giddiness of his will; he does not throw himself into his judgments; his genius leads him one way but 't is likely his trade or politics in quite another.
Animal experimentation is the blackest of all the black crimes that a man is at present committing... We should be able to refuse to live if the price of living be the torture of sentient beings... I abhor [animal] experimentation with my whole soul. All the scientific discoveries stained with innocent blood I count as of no consequence... The greatness of a nation and its moral progress can be judged by the way its animals are treated.
"It is essential to understand this point thoroughly: that the thing-in-itself, whether animal, vegetable, or mineral, is not only unknowable-it does not exist. This is important not only for sanity and peace of mind, but also for the most "practical" reasons of economics, politics, and technology.. This is not to say only that things exist in relation to one another, but that what we call "things" are no more than glimpses of a unified process. Certainly, this process has distinct features which catch our attention, but we must remember that distinction is not separation."
Compassion for animals is intimately associated with goodness of character, and it may be confidently asserted that he who is cruel to animals cannot be a good man.
Now and then we hear the wilder voices of the wilderness, from animals that in the hours of darkness do not fear the neighborhood of man: the coyotes wail like dismal ventriloquists, or the silence may be broken by the snorting and stamping of a deer.
Strictly speaking, no activity and no industry is possible without a certain amount of violence, no matter how little. Even the very process of living is impossible without a certain amount of violence. What we have to do is to minimize it to the greatest extent possible.