I believe that pity is a law like justice, and that kindness is a duty like uprightness. That which is weak has a right to the kindness and pity of that which is strong. In the relations of man with the animals...there is a great ethic, scarcely perceived as yet, which will at length break through into the light, and which will be the corollary and the complement to humans ethics. Are there not here unsounded depths for the thinker? Is one to think oneself mad because one has the sentiment of universal pity in one's heart?

With a tiny bit of effort, the nettle would be useful; if you neglect it, it becomes a pest. So then we kill it. How many men are like nettles My friends, there is no such thing as a weed and no such thing as a bad man. There are only bad cultivators.

Men become accustomed to poison by degrees.

Nothing is really small; whoever is open to the deep penetration of nature knows this.

Every blade has two edges; he who wounds with one wounds himself with the other.

Scepticism, that dry caries of the intelligence.

Humanity is our common lot. All men are made of the same clay. There is no difference, at least here on Earth, in the fate assigned to us. We come of the same void, inhabit the same flesh, are dissolved in the same ashes. But ignorance infecting the human substance turns it black, and that incurable blackness, gaining possession of the soul, becomes Evil.