Plutarch, Publicola
Bernadotte Perrin, Ed.

17. While Porsena was closely investing the city, a famine afflicted the Romans,¹ and another Tuscan army on its own account invaded their territory. Publicola, who was now consul for the third time, thought that Porsena must be met by a quiet and watchful resistance within the city; but he sallied out upon the other Tuscan army, engaged it, routed it, and slew five thousand of them.

The story of Mucius has been often and variously told, but I must give it as it seems most credible to me.² [2] He was a man endowed with every virtue, but most excellent in war. Designing to kill Porsena, he stole into his camp, wearing a Tuscan habit, and using a speech to correspond. After walking around the tribunal where the king was sitting within others, not knowing him certainly, and fearing to inquire about him, he drew his sword and slew that one of the group whom he thought most likely to be the king. [3] Upon this he was seized, and was being questioned, when a sort of pan containing live coals was brought to Porsena, who was about to offer sacrifice. Mucius held his right hand over the flames and, while the flesh was burning, stood looking at Porsena with a bold and steadfast countenance, until the king was overcome within admiration and released him, and handed him back his sword, reaching it down to him from the tribunal. Mucius stretched out his left hand and took it (on which account, they say, he received the surname of Scaevola, which means Left-handed). [4] Then he said that although he had conquered the fear which Porsena inspired, he was vanquished by the nobility which he displayed, and would reveal out of gratitude what he would not have disclosed under compulsion. ‘Three hundred Romans, then,’ said he, ‘with the same resolution as mine, are now prowling, about in thy camp and watching their opportunity. I was chosen by lot to make the first attempt upon thee, and I am not distressed at what has happened, so noble is the man whom I failed to kill, and so worthy to be a friend rather than an enemy of the Romans.’ [5] On hearing this, Porsena believed it to be true, and felt more inclined to come to terms, not so much, I suppose, through fear of the three hundred, as out of wondering admiration for the lofty spirit and bravery of the Romans.³

All other writers agree in giving this Mucius the surname of Scaevola, but Athenodorus, the son of Sandon, in his book addressed to Octavia, the sister of Augustus Caesar, says that his surname was Postumus.