"To obtain peace, it is necessary to become enlightened.
"However, it is wise always to foresee the least happy issue and to prepare to support the consequences.
"The man who thinks thus will be stronger than adversity and will know how to struggle with misfortune without allowing it to master him."
It is in these terms that Yoritomo initiates us into what he calls the mechanism of common sense; in other words, the art of acquiring by the simplest reasoning this quality dull as iron, but, like it, also solid and durable.
LESSON IX
COMMON SENSE AND ACTION
These qualities are two relatives very near of kin; but, just for this reason, they must not be confounded.
While common sense is applied to all the circumstances of life, practical sense is applicable to useful things.
Common sense admits a very subtle logic which is, at times, a little complex.
Practical sense reasons, starting from one point only; viz., material conveniences.