The two most powerful warriors are patience and time.

• patience

The simplest and shortest ethical precept is to be served by others as little as possible and to serve others as much as possible.

• service

The most difficult subjects can be explained to the most slow-witted man if he has not formed any idea of them already; but the simplest thing cannot be made clear to the most intelligent man if he is firmly persuaded that he knows already, without a shadow of doubt, what is laid before him.

• argument