Deiotarus being now an old man, had sent for Cato, to recommend his children and family to his protection; and as soon as he came, brought him presents of all sorts of things, which he begged and entreated him to accept. And his importunities displeased Cato so much, that though he came but in the evening, he stayed only that night, and went away early the next morning. After he was gone one day's journey, he found at Pessinus a yet greater quantity of presents provided for him there, and also letters from Deiotarus, entreating him to receive them, or at least to permit his friends to take them, who for his sake deserved some gratification, and could not have much done for them out of Cato's own means. Yet he would not suffer it, though he saw some of them very willing to receive such gifts, and ready to complain of his severity; but he answered, that corruption would never want pretense, and his friends should share with him in whatever he should justly and honestly obtain, and so returned the presents to Deiotarus.

When he took ship for Brundusium, his friends would have persuaded him to put his brother's ashes into another vessel; but he said, he would sooner part with his life than leave them, and so set sail. And as it chanced, he, we are told, had a very dangerous passage, though others at the same time went over safely enough.

After he was returned to Rome, he spent his time for the most part either at home, in conversation with Athenodorus, or at the forum, in the service of his friends. Though it was now the time that he should become quaestor, he would not stand for the place till he had studied the laws relating to it, and by inquiry from persons of experience, had attained a distinct understanding of the duty and authority belonging to it. With this knowledge, as soon as he came into the office, he made a great reformation among the clerks and under-officers of the treasury, people who had long practice and familiarity in all the public records and the laws, and, when new magistrates came in year by year, so ignorant and unskillful as to be in absolute need of others to teach them what to do, did not submit and give way, but kept the power in their own hands, and were in effect the treasurers themselves. Till Cato, applying himself roundly to the work, showed that he possessed not only the title and honor of a quaestor, but the knowledge and understanding and full authority of his office. So that he used the clerks and under-officers like servants, as they were, exposing their corrupt practices, and instructing their ignorance. Being bold impudent fellows, they flattered the other quaestors, his colleagues, and by their means endeavored to maintain an opposition against him. But he convicted the chiefest of them of a breach of trust in the charge of an inheritance, and turned him out of his place. A second he brought to trial for dishonesty, who was defended by Lutatius Catulus, at that time censor, a man very considerable for his office, but yet more for his character, as he was eminent above all the Romans of that age for his reputed wisdom and integrity. He was also intimate with Cato, and much commended his way of living. So perceiving he could not bring off his client, if he stood a fair trial, he openly began to beg him off. Cato objected to his doing this. And when he continued still to be importunate, "It would be shameful, Catulus," he said, "that the censor, the judge of all our lives, should incur the dishonor of removal by our officers." At this expression, Catalus looked as if he would have made some answer; but he said nothing, and either through anger or shame went away silent, and out of countenance. Nevertheless, the man was not found guilty, for the voices that acquitted him were but one in number less than those that condemned him, and Marcus Lollius, one of Cato's colleagues, who was absent by reason of sickness, was sent for by Catalus, and entreated to come and save the man. So Lollius was brought into court in a chair, and gave his voice also for acquitting him. Yet Cato never after made use of that clerk, and never paid him his salary, nor would he make any account of the vote given by Lollius. Having thus humbled the clerks, and brought them to be at command, he made use of the books and registers as he thought fit, and in a little while gained the treasury a higher name than the Senate-house itself; and all men said, Cato had made the office of a quaestor equal to the dignity of a consul. When he found many indebted to the state upon old accounts, and the state also in debt to many private persons, he took care that the public might no longer either do or suffer wrong; he strictly and punctually exacted what was due to the treasury, and as freely and speedily paid all those to whom it was indebted. So that the people were filled with sentiments of awe and respect, on seeing those made to pay, who thought to have escaped with their plunder, and others receiving all their due, who despaired of getting anything. And whereas usually those who brought false bills and pretended orders of the senate, could through favor get them accepted, Cato would never be so imposed upon, and in the case of one particular order, question arising, whether it had passed the senate, he would not believe a great many witnesses that attested it, nor would admit of it, till the consuls came and affirmed it upon oath.

There were at that time a great many whom Sylla had made use of as his agents in the proscription, and to whom he had for their service in putting men to death, given twelve thousand drachmas apiece. These men everybody hated as wicked and polluted wretches, but nobody durst be revenged upon them. Cato called everyone to account, as wrongfully possessed of the public money, and exacted it of them, and at the same time sharply reproved them for their unlawful and impious actions. After these proceedings, they were presently accused of murder, and being already in a manner prejudged as guilty, they were easily found so, and accordingly suffered; at which the whole people rejoiced, and thought themselves now to see the old tyranny finally abolished, and Sylla himself, so to say, brought to punishment.

Cato's assiduity also, and indefatigable diligence, won very much upon the people. He always came first of any of his colleagues to the treasury, and went away the last. He never missed any assembly of the people, or sitting of the senate; being always anxious and on the watch for those who lightly, or as a matter of interest, passed votes in favor of this or that person, for remitting debts or granting away customs that were owing to the state. And at length, having kept the exchequer pure and clear from base informers, and yet having filled it with treasure, he made it appear the state might be rich, without oppressing the people. At first he excited feelings of dislike and irritation in some of his colleagues, but after a while they were well contented with him, since he was perfectly willing that they should cast all the odium on him, when they declined to gratify their friends with the public money, or to give dishonest judgments in passing their accounts; and when hard pressed by suitors, they could readily answer it was impossible to do anything, unless Cato would consent. On the last day of his office, he was honorably attended to his house by almost all the people; but on the way he was informed that several powerful friends were in the treasury with Marcellus, using all their interest with him to pass a certain debt to the public revenue, as if it had been a gift. Marcellus had been one of Cato's friends from his childhood, and so long as Cato was with him, was one of the best of his colleagues in this office, but when alone, was unable to resist the importunity of suitors, and prone to do anybody a kindness. So Cato immediately turned back, and finding that Marcellus had yielded to pass the thing, he took the book, and while Marcellus silently stood by and looked on, struck it out. This done, he brought Marcellus out of the treasury, and took him home with him; who for all this, neither then, nor ever after, complained of him, but always continued his friendship and familiarity with him.

Cato after he had laid down his office, yet did not cease to keep a watch upon the treasury. He had his servants who continually wrote out the details of the expenditure, and he himself kept always by him certain books, which contained the accounts of the revenue from Sylla's time to his own quaestorship, which he had bought for five talents.