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.
My good friend, you are a citizen of Athens, a city which is very great and very famous for its wisdom and power - are you not ashamed of caring so much for the making of money and for fame and prestige, when you neither think nor care about wisdom and truth and the improvement of your soul?
For if God is man's chief good, which you cannot deny, it clearly follows, since to seek the chief good is to live well, that to live well is nothing else but to love God with all the heart, with all the soul, with all the mind.
What I think about vivisection is that if people admit that they have the right to take or endanger the life of living beings for the benefit of many, there will be no limit to their cruelty.