Maximillien Robespierre, a leading Jacobin deputy in the Convention, had originally opposed the trial, believing that to try the King was to imply the possibility of his innocence. Nevertheless, once it was under way, Robespierre took the lead in arguing that on trial was not "the man Louis Capet" but the institution of the monarchy . He argued that since the Revolution essentially concerned the sovereignty of the people, a Revolution could not coexist with a king, and thus, he reached his famous conclusion that Louis must die, so that the Revolution could live.
Citizens, without realizing it the Assembly has been lead far from the true question. There is no trial to be conducted here. Louis is not accused and you are not judges. You are, as you can only be, the nation's statesmen and representatives. No verdict is required, either for or against a man. Rather, a step aimed at the public safety needs to be taken, an act of salvation for the nation. In a Republic a deposed king is good for only one of two things: He either disrupts the peace of the state and weakens its freedom, or he strengthens both simultaneously. I assert that the nature of the deliberations to date are directly at odds with this latter goal. In fact, what rational course of action is called for to solidify a newborn Republic? Is it not to etch an eternal contempt for royalty into everyone's soul and mute the King's supporters? . . .
Louis was the King, and the Republic is established. The vital question that occupies you here is resolved by these few words: Louis has been deposed by his crimes. He denounced the French people as rebels, and to punish them he called upon the arms of his fellow tyrants. Victory and the people have decided that he alone was the rebel. Consequently, Louis cannot be judged. Either he is already condemned, or else the Republic is not absolved. To suggest that Louis XVI be tried in any way whatsoever is to regress toward royal and constitutional despotism. A proposal such as this, since it would question the legitimacy of the Revolution itself, is counterrevolutionary. In actuality, if Louis can still be brought to trial, he might yet be acquitted. In truth, he is presumed innocent until he has been found guilty. If Louis is acquitted, what then becomes of the Revolution? If Louis is innocent, all defenders of liberty are then slanderers. . . .
Citizens, defend yourselves against [tyranny]! False ideas have deceived you. . . . You are confusing the state of a people in the midst of a revolution with the state of a people whose government is firmly established. You are confusing a nation that punishes a public official while maintaining its form of government with a nation that destroys the government itself. . . .
When a nation has been forced to resort to its right of insurrection, its relationship with the tyrant is then determined by the law of nature. By what right does the tyrant invoke the social contract? He abolished it! The nation, if it deems proper, may preserve the contract insofar as it concerns the relations between citizens. But the end result of tyranny and insurrection is to completely break all ties with the tyrant and to reestablish the state of war between the tyrant and the people. Tribunals and judiciary procedure are designed only for citizens. . . .
Insurrection is the real trial of a tyrant. His sentence is the end of his power, and his sentence is whatever the People's liberty requires.
The trial of Louis XVI? What is this trial if not an appeal from the insurrection to some tribunal or assembly? When the people have dethroned a king, who has the right to revive him, thereby creating a new pretext for riot and rebellion—and what else could result from such actions? By giving a platform to those championing Louis XVI, you rekindle the dispute between despotism and liberty and sanction blasphemy of the Republic and the people . . . for the right to defend the former despot includes the right to say anything that sustains his cause. You reawaken all the factions, reviving and encouraging a dormant royalism. One could easily take a position for or against. What could be more legitimate or more natural than to everywhere spread the maxims that his defenders could openly profess in the courtroom, and within your very forum? What manner of Republic is it whose founders solicit its adversaries from all quarters to attack it in its cradle? . . .
Representatives, what is important to the people, what is important to yourselves, is that you fulfill the duties with which the people have entrusted you. The Republic has been proclaimed, but have you delivered it to us. You have yet to pass a single law deserving of that title. You have yet to reform a single abuse of despotism. Remove but the name and we have tyranny still, with even more vile factions and even more immoral charlatans, while there is new tumultuous unrest and civil war. The Republic! And Louis still lives! And you continue to place the King between us and liberty! Our scruples risk turning us into criminals. Our indulgence for the guilty risks our joining him in his guilt. . . .
Regretfully I speak this fatal truth—Louis must die because the nation must live. Among a peaceful people, free and respected both within their country and from without, it would be possible to listen to the counsel of generosity which you have received. But a people that is still fighting for its freedom after so much sacrifice and so many battles; a people for whom the laws are not yet irrevocable except for the needy; a people for whom tyranny is still a crime subject to dispute—such a people should want to be avenged. The generosity which you are encouraged to show would more closely resemble that of a gang of brigands dividing their spoils.
I propose that you take immediate legal action on the fate of Louis XVI. . . . I ask that the National Convention state that from this moment on he is a traitor to the French nation and a criminal against humanity. I ask that for these reasons, that in the very place where the martyrs of liberty gave their lives on the tenth of August, he be made an example for the world. And I ask that this memorable event be consecrated by a monument that will nurture in the hearts of all people a sense of their own rights and a horror of tyrants, as well as nurture in any tyrant's soul the salutary terror of the people's justice.
Source: M. J. Mavidal and M. E. Laurent, eds., Archives parlementaires de 1787 à 1860, première série (1787 à 1799), 2d ed., 82 vols. (Paris: Dupont, 1879