Horses and pigs, on hearing a cry of distress from one of their number, rush to the spot whence it comes.
What descriptions I might give of their marriages, the tenderness of the males towards the females, and the fidelity of their loves! Let us add, however,--to be entirely just--that these touching demonstrations of society, fraternity, and love of neighbor, do not prevent the animals from quarrelling, fighting, and outrageously abusing one another while gaining their livelihood and showing their gallantry; the resemblance between them and ourselves is perfect.
The social instinct, in man and beast, exists to a greater or less degree--its nature is the same.

Man has the greater need of association, and employs it more; the animal seems better able to endure isolation.
In man, social needs are more imperative and complex; in the beast, they seem less intense, less diversified, less regretted.

Society, in a word, aims, in the case of man, at the preservation of the race and the individual; with the animals, its object is more exclusively the preservation of the race.
As yet, we have met with no claim which man can make for himself alone.
The social instinct and the moral sense he shares with the brutes; and when he thinks to become god-like by a few acts of charity, justice, and devotion, he does not perceive that in so acting he simply obeys an instinct wholly animal in its nature.

As we are good, loving, tender, just, so we are passionate, greedy, lewd, and vindictive; that is, we are like the beasts.

Our highest virtues appear, in the last analysis, as blind, impulsive instincts.