The one exclusive sign of thorough knowledge is the power of teaching.

The one exclusive sign of thorough knowledge is the power of teaching.

Your best teacher is your last mistake.

Your best teacher is your last mistake.

Few things are impossible to diligence and skill ... Great works are performed, not by strength, but perseverance.

Few things are impossible to diligence and skill ... Great works are performed, not by strength, but perseverance.

Nothing is so difficult that diligence cannot master it.

Nothing is so difficult that diligence cannot master it.

Diligence is the mother of good luck.

Diligence is the mother of good luck.

Experience is a good teacher, but she sends in terrific bills.

Experience is a good teacher, but she sends in terrific bills.

Decay is inherent in all compounded things. Strive on with diligence.

Decay is inherent in all compounded things. Strive on with diligence.

A great fortune depends on luck, a small one on diligence.

A great fortune depends on luck, a small one on diligence.

Teaching is the greatest act of optimism.

Teaching is the greatest act of optimism.