During the summer the second violent canvass of Catiline on a reckless program of revolution only made Cicero a more confirmed conservative. To save the state from revolution he had himself to propose a senatorial order of martial law in October, a measure he would doubtless have fought three years before, and under its provisions he had the conspirators put to death, an act which made him the prime defender and advocate of the central optimate theory, and later caused his banishment at the hands of Caesar’s democratic coalition. Thus experience and circumstances had in three years turned the avowed democrat into an extreme optimate. It is needless to follow his career in detail: the desertion of his coalition by the knights because Caesar offered them what they desired, his banishment, which only confirmed his convictions that he was right, his failure on his return to undo Caesar’s popular legislation because the senate feared Caesar and dared not follow Cicero. He still clung for a while to his new doctrine of the senate’s importance, as the _Pro Sestio_ proves, but it was a futile policy. The senators, fearing Caesar, failed to respond. He saw then, if not before, that the senate could not rule Rome. Cicero now retired from active political life and found time to think and draw conclusions from his experiences for a carefully considered review of Roman political needs. In the _De Republica_, which he wrote in 54-1, shortly before the Civil War, he carefully reviewed the history of the Roman constitution in order to lay a sound foundation for a durable and reasonable program in case the senate and people should ever regain the freedom of action which the first “triumvirate” had taken away. There was some hope that such a program might have a chance, for Crassus was out of reach and Pompey and Caesar were noticeably falling apart. In this book he shows that Rome had definitely rejected autocratic government, and that, as Polybius had already seen, it had combined the machinery of popular sovereignty with aristocratic checks under strong but short-term executives. In showing that this form was historically based and that it had operated well in the happiest days of Rome, Cicero became convinced that he must give a larger place in his book to the popular assembly than he had been willing to accord it since the days of Catiline. He says with rather surprising firmness that the populace must have liberty of action or they will revolt, and that liberty was a natural right that no man of intelligence could propose to destroy. This is virtually a confession that he had gone too far toward oligarchy in his own consulship. He knew now that if the nobles had been more friendly to the populace, Caesar would not have been able to seize control. He therefore admits the theory of popular sovereignty which could not be denied after the events of 59, but he also seeks for some method by which to check the danger of such a concession.