知道
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.
To know good and evil is not enough； one must also do them.
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.
He who knows only his side of the case knows little of that.