The desires， and other passions of man， in themselves， are in his own power； his real difficulties are， to know when they are to be controlled， and when not.
As long as man continues to be the ruthless destroyer of lower living beings， he will never know health or peace. For as long as men massacre animals， they will kill each other.
In the part of this universe that we know there is great injustice， and often the good suffer， and often the wicked prosper， and one hardly knows which of those is the more annoying.
Three things are necessary for the salvation of man: to know what he ought to believe； to know what he ought to desire； and to know what he ought to do.
