Book IV, Chapter VI
The inflexibility of the laws, which prevents them from adapting themselves to circumstances, may, in certain cases, render them disastrous, and make them bring about, at a time of crisis, the ruin of the State. The order and slowness of the forms they enjoin require a space of time which circumstances sometimes withhold. A thousand cases against which the legislator has made no provision may present themselves, and it is a highly necessary part of foresight to be conscious that everything cannot be foreseen.
It is wrong therefore to wish to make political institutions so strong as to render it impossible to suspend their operation. Even Sparta allowed its laws to lapse.
However, none but the greatest dangers can counter-balance that of changing the public order, and the sacred power of the laws should never be arrested save when the existence of the country is at stake. In these rare and obvious cases, provision is made for the public security by a particular act entrusting it to him who is most worthy. This commitment may be carried out in either of two ways, according to the nature of the danger.
If increasing the activity of the government is a sufficient remedy, power is concentrated in the hands of one or two of its members: in this case the change is not in the authority of the laws, but only in the form of administering them. If, on the other hand, the peril is of such a kind that the paraphernalia of the laws are an obstacle to their preservation, the method is to nominate a supreme ruler, who shall silence all the laws and suspend for a moment the sovereign authority. In such a case, there is no doubt about the general will, and it is clear that the people's first intention is that the State shall not perish. Thus the suspension of the legislative authority is in no sense its abolition; the magistrate who silences it cannot make it speak; he dominates it, but cannot represent it. He can do anything, except make laws.
The first method was used by the Roman senate when, in a consecrated formula, it charged the consuls to provide for the safety of the Republic. The second was employed when one of the two consuls nominated a dictator:  a custom Rome borrowed from Alba.
During the first period of the Republic, recourse was very often had to the dictatorship, because the State had not yet a firm enough basis to be able to maintain itself by the strength of its constitution alone. As the state of morality then made superfluous many of the precautions which would have been necessary at other times, there was no fear that a dictator would abuse his authority, or try to keep it beyond his term of office. On the contrary, so much power appeared to be burdensome to him who was clothed with it, and he made all speed to lay it down, as if taking the place of the laws had been too troublesome and too perilous a position to retain.
It is therefore the danger not of its abuse, but of its cheapening, that makes me attack the indiscreet use of this supreme magistracy in the earliest times. For as long as it was freely employed at elections, dedications and purely formal functions, there was danger of its becoming less formidable in time of need, and of men growing accustomed to regarding as empty a title that was used only on occasions of empty ceremonial.
Towards the end of the Republic, the Romans, having grown more circumspect, were as unreasonably sparing in the use of the dictatorship as they had formerly been lavish. It is easy to see that their fears were without foundation, that the weakness of the capital secured it against the magistrates who were in its midst; that a dictator might, in certain cases, defend the public liberty, but could never endanger it; and that the chains of Rome would be forged, not in Rome itself, but in her armies. The weak resistance offered by Marius to Sulla, and by Pompey to Cæsar, clearly showed what was to be expected from authority at home against force from abroad.
This misconception led the Romans to make great mistakes; such, for example, as the failure to nominate a dictator in the Catilinarian conspiracy. For, as only the city itself, with at most some province in Italy, was concerned, the unlimited authority the laws gave to the dictator would have enabled him to make short work of the conspiracy, which was, in fact, stifled only by a combination of lucky chances human prudence had no right to expect.
Instead, the senate contented itself with entrusting its whole power to the consuls, so that Cicero, in order to take effective action, was compelled on a capital point to exceed his powers; and if, in the first transports of joy, his conduct was approved, he was justly called, later on, to account for the blood of citizens spilt in violation of the laws. Such a reproach could never have been levelled at a dictator. But the consul's eloquence carried the day; and he himself, Roman though he was, loved his own glory better than his country, and sought, not so much the most lawful and secure means of saving the State, as to get for himself the whole honour of having done so.  He was therefore justly honoured as the liberator of Rome, and also justly punished as a law-breaker. However brilliant his recall may have been, it was undoubtedly an act of pardon.
However this important trust be conferred, it is important that its duration should be fixed at a very brief period, incapable of being ever prolonged. In the crises which lead to its adoption, the State is either soon lost, or soon saved; and, the present need passed, the dictatorship becomes either tyrannical or idle. At Rome, where dictators held office for six months only, most of them abdicated before their time was up. If their term had been longer, they might well have tried to prolong it still further, as the decemvirs did when chosen for a year. The dictator had only time to provide against the need that had caused him to be chosen; he had none to think of further projects.
 The nomination was made secretly by night, as if there were something shameful in setting a man above the laws.
 That is what he could not be sure of, if he proposed a dictator; for he dared not nominate himself, and could not be certain that his colleague would nominate him.