whole question turns on whether the doctrine was true that the _senatus
consultum ultimum_ gave the consul the right of inflicting death upon
citizens without trial, _i.e._, without appeal to the people, on the
analogy of the dictator _seditionis sedandae causa_, thus practically
defeating that most ancient and cherished safeguard of Roman liberty,
the _ius provocationis_. The precedents were few, and scarcely such as
would appeal to popular approval. The murder of Tiberius Gracchus had
been _ex post facto_ approved by the senate in B.C. 133-2. In the case
of Gaius Gracchus, in B.C. 121, the senate had voted _uti consul Opimius
rempublicam defenderet_, and in virtue of that the consul had authorized
the killing of Gaius and his friends: thus for the first time exercising
_imperium sine provocatione_. Opimius had been impeached after his year
of office, but acquitted, which the senate might claim as a confirmation
of the right, in spite of the _lex_ of Gaius Gracchus, which confirmed
the right of _provocatio_ in all cases. In B.C. 100 the tribune
Saturninus and the praetor Glaucia were arrested in consequence of a
similar decree, which this time joined the other magistrates to the
consuls as authorized to protect the Republic: their death, however, was
an act of violence on the part of a mob. Its legality had been impugned
by Caesar's condemnation of Rabirius, as _duovir capitalis_, but to a
certain extent confirmed by the failure to secure his conviction on the
trial of his appeal to the people. In B.C. 88 and 83 this decree of the
senate was again passed, in the first case in favour of Sulla against
the tribune Sulpicius, who was in consequence put to death; and in the
second case in favour of the consuls (partisans of Marius) against the
followers of Sulla. Again in B.C. 77 the decree was passed in
consequence of the insurrection of the proconsul Lepidus, who, however,
escaped to Sardinia and died there.

In every case but one this decree had been passed against the popular
party. The only legal sanction given to the exercise of the _imperium
sine provocatione_ was the acquittal of the consul Opimius in B.C. 120.
But the jury which tried that case probably consisted entirely of
senators, who would not stultify their own proceedings by condemning
him. To rely upon such precedents required either great boldness (never
a characteristic of Cicero), or the most profound conviction of the
essential righteousness of the mea