5. Homines dum docent discunt
Men learn while they teach
Bonitas non est pessimis esse meliorem
It is not goodness to be better than the worst
Errare humanum est. Perseverare diabolicum
To err is human, to persist is diabolical
Diligentia maximum etiam mediocris ingenio subsidium
Diligence is a great help even to a mediocre intelligence