Plutarch, The Life of Cato the Younger 16

After his return to Rome, he spent most of his time at home in the company of Athenodorus,​ or in the forum assisting his friends. And though the office of quaestor was open to him, he would not become a candidate for it until he had read the laws relating to the quaestor­ship, learned all the details of the office from those who had had experience in it, and formed a general idea of its power and scope. 

Therefore, as soon as he had been instated in the office,​ he made a great change in the assistants and clerks connected with the treasury. These were fully conversant with the public accounts and the laws relative thereto, and so, when they received as their superior officers young men whose inexperience and ignorance made it really needful that others should teach and tutor them, they would not surrender any power to such superiors, but were superiors themselves. 

Now, however, Cato applied himself with energy to the business, not having merely the name and honor of a superior official, but also intelligence and rational judgement. He thought it best to treat the clerks as assistants, which they really were, sometimes convicting them of their evil practices, and sometimes teaching them if they erred from inexperience. 

But they were bold fellows, and tried to ingratiate themselves with the other quaestors, while they waged war upon Cato. Therefore the chief among them, whom he found guilty of a breach of trust in the matter of an inheritance, was expelled from the treasury by him and a second was brought to trial for fraud. 

This person Catulus Lutatius the censor came forward to defend, but most of all from his virtue, being thought to surpass all Romans in justice and discretion; he also commended Cato's way of living and was intimate with him. Accordingly, when Catulus had lost his case on its merits and began to beg openly for the acquittal of his client, Cato tried to stop him from doing this. 

And when Catulus was all the more importunate, Cato said: "It would be a shameful thing, Catulus, if you, who are the censor, and should scrutinize our lives, wert put out of court by our bailiffs." 

When Cato had uttered these words, Catulus fixed his eyes upon him as if he would make reply; he said nothing, however, but either from anger or from shame went off in silence, much perplexed. 

However, the man was not convicted, but when the votes for condemnation exceeded those for acquittal by a single ballot, and one Marcus Lollius, a colleague of Cato, was kept by sickness from attending the trial, Catulus sent to him and begged him to help the man. So Lollius was brought in a litter after the trial and cast the vote that acquitted. 

Notwithstanding this, Cato would not employ the clerk, or give him his pay, or in any way take the vote of Lollius into the reckoning. 

IMAGE: Jacques Grasset de Saint-Sauveur, A Roman Quaestor (1796)