In judging means, look only to the end: if the state goes under, all is lost. Hence the famous paragraph in the forty-first chapter of the third book of The Discourses where he says:
When the very safety of the country depends upon the resolution to be taken, no considerations of justice or injustice, humanity or cruelty, not of glory or of infamy, should be allowed to prevail. But putting all other considerations aside, the only question should be “What course will save the life and liberty of the country?”
CHAPTER XLI.—That our Country is to be defended by Honour or by Dishonour; and in either way is well defended.
The consuls together with the whole Roman army fell, as I have related, into the hands of the Samnites, who imposed on them the most ignominious terms, insisting that they should be stripped of their arms, and pass under the yoke before they were allowed to return to Rome.
The consuls being astounded by the harshness of these conditions and the whole army overwhelmed with dismay, Lucius Lentulus, the Roman lieutenant, stood forward and said, that in his opinion they ought to decline no course whereby their country might be saved; and that as the very existence of Rome depended on the preservation of her army, that army must be saved at any sacrifice, for whether the means be honourable or ignominious, all is well done that is done for the defence of our country. And he said that were her army preserved, Rome, in course of time, might wipe out the disgrace; but if her army were destroyed, however gloriously it might perish, Rome and her freedom would perish with it. In the event his counsel was followed.
Now this incident deserves to be noted and pondered over by every citizen who is called on to advise his country; for when the entire safety of our country is at stake, no consideration of what is just or unjust, merciful or cruel, praiseworthy or shameful, must intervene. On the contrary, every other consideration being set aside, that course alone must be taken which preserves the existence of the country and maintains its liberty.