He assembled a coalition of malcontents – aristocrats who had been denied political advancement by the voters, dispossessed farmers, and indebted veterans of Sulla – and planned to seize the consulship from Cicero and Antonius by force.
[12] Some were frustrated candidates for municipal elections, some may have been motivated by debts, some sought profit in the chaos, and others were members of declining aristocratic families like Catiline.
[15][16] The ancient sources generally credit their involvement in the conspiracy with large debts that Catiline's putsch were supposedly to erase.
[23] With renewed demand for capital in the aftermath of stability secured by Pompey's victory in the Third Mithridatic War, moneylenders would have called in debts and increased interest rates, driving men into bankruptcy.
The first concrete evidence was provided by Marcus Licinius Crassus, who handed over letters on 18 or 19 October which described plans to massacre prominent citizens.
[26][27] In response, the senate passed a decree declaring a tumultus (a state of emergency) and, after receipt of the reports of armed men gathering in Etruria, carried the senatus consultum ultimum instructing the consuls to do whatever it took to respond to the crisis.
In response, Cicero dispatched two nearby proconsuls and two praetors to respond to the possibility of armed insurrection with permission to levy troops and orders to maintain night watches.
[32] But after messages from Etruria connected him directly to the uprising, he was indicted under the lex Plautia de vi (public violence) in early November.
[33] After the attempts on Cicero's life failed on 7 November 63 BC, he assembled the senate and delivered his first oration against Catiline, publicly denouncing the conspiracy.
Catiline attempted to speak in his defence – attacking Cicero's ancestry – but was shouted down and promptly left the city to join Manlius' men in Etruria.
[31][37] Cassius Dio's history adds that Catiline was promptly convicted on the pending charges of vis (public violence).
Cicero, using the Allobroges' envoys as double agents, sought their cooperation in identifying as many members of the conspiracy in the city as possible.
After the Gallic envoys divulged all they knew with promises of immunity before the senate, the prisoners confessed their guilt; Lentulus was forced to resign his magistracy and the others were committed to house arrest.
[44] Cicero, as consul, had been empowered by the previously passed senatus consultum ultimum to take whatever steps he thought necessary to safeguard the state, but such decrees, while lending moral support for consular action, did not grant any kind of formal immunity.
[50] Cicero purports he then interrupted proceedings to deliver a speech urging immediate action,[b] but the tide did not turn towards execution until Cato the Younger spoke.
[53] Sallust's version has Cato rail against moral decline in the state and has him criticising the senators for failing to be strict and harsh like their ancestors.
With the appeal that swift execution would cause defections among the Catilinarians and exaggerated claims that Catiline was to be upon them imminently, Cato's speech carried the day.
[65][66] Views on Cicero's success in defending the republic are mixed: while Cicero argued that he had saved the commonwealth and many scholars have accepted his defence of necessary exigency, Harriet Flower, a classicist, writes he did so "by circumventing due process and the civil rights of citizens" while also revealing "the consul's complete lack of confidence in the court system on which the New Republic of Sulla was supposed to be based".
[74][76][77] Sallust's overarching focus on moral decline as a cause of the republic's collapse has him paint an ahistorical portrait of Catiline that elides details in favour of his larger narrative.
J. T. Ramsey, in a commentary on the monograph, writes:[78] S. [Sallust] fails to allow for a gradual shift in Catiline's strategy and aims as his hopes of reaching the consulship faded, because S. prefers to present Catiline as a through-going villain, the product of the corrupt age, who was bent on the destruction of the state from the very beginning...[78] And more problematically, Sallust's reliance on Cicero's one-sided narrative leads him to accept Cicero's invective uncritically, exacerbating the portrait's hostility.
[81] For example, Louis E. Lord in the introduction to the 1937 Loeb Classical Library translation of Cicero's Catilinarian orations calls it "one of the best known and least significant episodes in Roman history".
[82] Scholars have also criticised over-estimation of the importance of Catiline's insurrection,[83] but others also stress that the affair was not meaningless and that it jolted the republic into action.
The government was in no real danger of toppling; the conspiracy, in fact, strengthened awareness of a common interest in order and stability.
The shape of the social structure remained basically unaffected... but the grievances had been brought to public attention... prominent leaders recognised the utility of responding to needs exposed in the Catilinarian affair.
This view is criticised as uncritically accepting confusing and empty ancient political slogans while ignoring Catiline's Sullan bona fides.
[86][87] While sources sometimes put popularis speeches into the mouths of Catiline and others, the dyadic nature of the Roman constitution forced justification of anti-senatorial policies by appeal to popular sovereignty.
[95] After detailing Catiline's purported plan, Waters argues that the description given of it is prima facie unbelievable and that, if true, the conspirators would have been implausibly incompetent.
[96] He argues that Catiline was forced to depart Rome under a cloud of false allegations to Etruria, where he made common cause with a pre-existing group of rebels to fight against Cicero's political dominance.
[99] Robin Seager argued in 1973 that Catiline's involvement in a plot against the state postdates Cicero's First Catilinarian and that when he left Rome in November, he had not yet fully committed to any rebellion.