Cicero continues his philosophical writing with a cosmological work, On the Universe, which he seems to have abandoned in favor of the dialogue On the Nature of the Gods, which set out and refuted the theologies of the Epicureans and Stoics. This was supplemented by On Divination, a dialogue between Cicero and his brother, Quintus. He also wrote the short dialogue On Old Age to honor his friend Atticus on his sixty-fifth birthday. His last quasi-forensic speech was a defense before Caesar of the Galatian tetrarch Deiotarus; the matter was still pending at Caesar’s death. He continued to attend meetings of the senate but was privately critical of the hollowing out of republican institutions under Caesar’s dictatorship. Caesar’s assassination on the Ides of March raised brief hopes of a return to republican patterns of government, but Mark Antony, who had been Caesar’s co-consul, was quickly able to reassert control.

Cicero was mostly disappointed by the news from Rome, especially the fact that the consuls Antony and Dolabella had five-year governorships voted for them in an assembly. Cicero, meanwhile, cultivated A. Hirtius, designated consul for 43, with the dedication of the work On Fate. He also wrote On Glory, with reflections on Caesar’s short-lived glory, and the Topics for his friend Trebatius. His plan to visit his son, who was studying philosophy in Athens, having been thwarted by adverse winds, he resolved to return to Rome to join the opposition. His First Philippic, delivered on September 2, politely criticizes Antony’s policies. When Antony replied with a searing attack on Cicero, the orator replied in the undelivered Second Philippic. After writing On Duties, dedicated to his son, he returned to Rome and argued in the Third Philippic for regularizing the commands of Octavian and D. Brutus in opposition to Antony, an argument summarized before the people in the Fourth Philippic.

Cicero, though back in Rome, still had to regain control of his property, the Palatine house having been destroyed and replaced by a temple of Libertas (“Liberty”) by Clodius. The case was difficult, since property properly dedicated to a god was not to be put to profane use. Cicero argued his case before the college of pontiffs and won them over, as well as the senate, which returned the site to him and appropriated funds for reconstruction. In the new year, Cicero was busy in the courts, defending his political ally P. Sestius against a charge of violence and his protégé M. Caelius Rufus against the same charge. The two speeches both won acquittals and rank among his finest. Cicero’s forensic successes led him to reassert himself politically, but the three-man coalition (Caesar, Pompey, Crassus) was reaffirmed at the Council of Luca, and Cicero had to back down.

The Sicilians requested that Cicero prosecute C. Verres, who had governed the province corruptly from 73 to 71, for extortion. Cicero, who was simultaneously a candidate for aedile, agreed. Verres was represented by Hortensius, who was Rome’s leading advocate. Cicero’s right to prosecute was opposed by Q. Caecilius, who was put forward as a collusive prosecutor by Verres. Cicero defeated Caecilius in a preliminary trial (divinatio). He was also elected aedile, in spite of bribery deployed against him by Verres. At trial, Cicero confined himself to a brief opening speech summarizing the charges and then presented a long parade of witnesses. When the trial was adjourned in mid-August 70, it was already clear that Verres’ case was hopeless, and he went into exile. Cicero published the massive material he had gathered in a large corpus of seven speeches and was henceforth the acknowledged leader of the Roman bar.

Under Caesar’s dictatorship, Cicero returned to his literary pursuits. This year, a series of works flowed from his pen dedicated to M. Brutus: Brutus, a historical survey of Roman orators; the Stoic Paradoxes, which aimed to show that Stoic doctrines could be presented in a more accessible way; the Cato, an encomium of Brutus’ uncle who had committed suicide rather than surrendering to Caesar; and the Orator, an exploration of the characteristics of the ideal orator. In the fall, Caesar pardoned M. Marcellus, who, like Cicero, was a consular who had joined the Pompeian side. Cicero delivered a speech of thanks in the senate, which also included advice about future actions. He also defended another ex-Pompeian, Q. Ligarius, in both private and public hearings before Caesar. His theoretical writing turned back to philosophy, with the dialogue Hortensius, probably also dedicated to Brutus, a protreptic or argument for the study of philosophy.