Freedom in the practical sense is the independence of the power of choice from necessitation by impulses of sensibility
Immanuel KantAct only according to that maxim whereby you can at the same time will that it should become a universal law.
Immanuel Kantcruelty 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.
Immanuel Kant