Quotes from work
De Inventione

Marcus Tullius Cicero

De Inventione is a handbook for orators that Cicero composed when he was still a young man. Quintillian tells us that Cicero considered the work rendered obsolete by his later writings. Originally four books in all, only two have survived into modern times. It is also credited with the first recorded use of the term "liberal arts" or artes liberales, though whether Cicero coined the term is unclear. The text also defines the concept of dignitas: dignitas est alicuius honesta et cultu et honore et verecundia digna auctoritas.

“for it is not having insufficient knowledge, but persisting a long time in insufficient knowledge that is shameful; since the one is assumed to be a disease common to all, but the other is assumed to be a flaw to an individual.”
non enim parum cognosse, sed in parum cognito stulte et diu perseverasse turpe est, propterea quod alterum communi hominum infirmitati alterum singulari cuiusque vitio est attributum.

Marcus Tullius Cicero De Inventione

De Inventione, Section 2.9.3
Variant: Any man can make mistakes, but only a fool persists in his error.