Cato, being scurrilously ...

Cato, being scurrilously treated by a low and vicious fellow, quietly said to him, \
Cato, being scurrilously treated by a low and vicious fellow, quietly said to him, "A contest between us is very unequal, for thou canst bear ill language with ease, and return it with pleasure; but to me it is unusual to hear, and disagreeable to speak it." There are none more abusive to others than they that lie most open to it themselves; but the humor goes round, and he that laughs at me today will have somebody to laugh at him tomorrow.

Quotes from the same author

If one does not know to which port one is sailing, no wind is favorable.
One of the most beautiful qualities of true friendship is to understand and to be understood.
Luck is what happens when preparation meets opportunity.
The conditions of conquest are always easy. We have but to toil awhile, endure awhile, believe always, and never turn back.
Begin at once to live and count each separate day as a separate life.