Life is life - whether in a cat, or dog or man. There is no difference there between a cat or a man. The idea of difference is a human conception for man's own advantage.
cruelty to animals is contrary to man's duty to himself, because it deadens in him the feeling of sympathy for their sufferings, and thus a natural tendency that is very useful to morality in relation to other human beings is weakened.
The assumption that animals are without rights, and the illusion that our treatment of them has no moral significance, is a positively outrageous example of Western crudity and barbarity. Universal compassion is the only guarantee of morality.
In every philosophical school, three thinkers succeed one another in the following way: the first produces out of himself the sapand seed, the second draws it out into threads and spins a synthetic web, and the third waits in this web for the sacrificial victims that are caught in it--and tries to live off philosophy.
The Greeks, with their truly healthy culture, have once and for all justified philosophy simply by having engaged in it, and having engaged in it more fully than any other people.