But upon the general separation into two factions, when, Pompey and Caesar taking up arms against one another, the whole empire was turned into confusion, it was commonly believed that he would take Caesar's side; for his father in past time had been put to death by Pompey. But he, thinking it his duty to prefer the interest of the public to his own private feelings, and judging Pompey's to be the better cause, took part with him; though formerly he used not so much as to salute or take any notice of Pompey, if he happened to meet him, esteeming it a pollution to have the least conversation with the murderer of his father. But now, looking upon him as the general of his country, he placed himself under his command, and set sail for Cilicia in quality of lieutenant to Sestius, who had the government of that province. But finding no opportunity there of doing any great service, and hearing that Pompey and Caesar were now near one another and preparing for the battle upon which all depended, he came of his own accord to Macedonia to partake in the danger. At his coming it is said that Pompey was so surprised and so pleased that, rising from his chair in the sight of all who were about him, he saluted and embraced him, as one of the chiefest of his party. All the time that he was in the camp, excepting that which he spent in Pompey's company, he employed in reading and in study, which he did not neglect even the day before the great battle. It was the middle of summer, and the heat was very great, the camp having been pitched near some marshy ground, and the people that carried Brutus's tent were a long while before they came. Yet though upon these accounts he was extremely harassed and out of order, having scarcely by the middle of the day anointed himself and eaten a sparing meal, whilst most others were either laid to sleep or taken up with the thoughts and apprehensions of what would be the issue of the fight, he spent his time until the evening in writing an epitome of Polybius.
It is said that Caesar had so great a regard for him that he ordered his commanders by no means to kill Brutus in the battle, but to spare him, if possible, and bring him safe to him, if he would willingly surrender himself; but if he made any resistance, to suffer him to escape rather than do him any violence. And this he is believed to have done out of a tenderness to Servilia, the mother of Brutus; for Caesar had, it seems, in his youth been very intimate with her, and she passionately in love with him; and, considering that Brutus was born about that time in which their loves were at the highest, Caesar had a belief that he was his own child. The story is told that, when the great question of the conspiracy of Catiline, which had like to have been the destruction of the commonwealth, was debated in the senate, Cato and Caesar were both standing up, contending together on the decision to be come to; at which time a little note was delivered to Caesar from without, which he took and read silently to himself. Upon this, Cato cried out aloud, and accused Caesar of holding correspondence with and receiving letters from the enemies of the commonwealth; and when many other senators exclaimed against it, Caesar delivered the note as he had received it to Cato, who reading it found it to be a love-letter from his own sister Servilia, and threw it back again to Caesar with the words, "Keep it, you drunkard," and returned to the subject of the debate. So public and notorious was Servilia's love to Caesar.
After the great overthrow at Pharsalia, Pompey himself having made his escape to the sea, and Caesar's army storming the camp, Brutus stole privately out by one of the gates leading to marshy ground full of water and covered with reeds, and, travelling through the night, got safe to Larissa. From Larissa he wrote to Caesar who expressed a great deal of joy to hear that he was safe, and, bidding him come, not only forgave him freely, but honoured and esteemed him among his chiefest friends. Now when nobody could give any certain account which way Pompey had fled, Caesar took a little journey along with Brutus, and tried what was his opinion herein, and after some discussion which passed between them, believing that Brutus's conjecture was the right one, laying aside all other thoughts, he set out directly to pursue him towards Egypt. But Pompey, having reached Egypt, as Brutus guessed his design was to do, there met his fate.
Brutus in the meantime gained Caesar's forgiveness for his friend Cassius; and pleading also in defence of the king of the Lybians, though he was overwhelmed with the greatness of the crimes alleged against him, yet by his entreaties and deprecations to Caesar in his behalf, he preserved to him a great part of his kingdom. It is reported that Caesar, when he first heard Brutus speak in public, said to his friends, "I know not what this young man intends, but, whatever he intends, he intends vehemently." For his natural firmness of mind, not easily yielding, or complying in favour of every one that entreated his kindness, once set into action upon motives of right reason and deliberate moral choice, whatever direction it thus took, it was pretty sure to take effectively, and to work in such a way as not to fail in its object. No flattery could ever prevail with him to listen to unjust petitions: and he held that to be overcome by the importunities of shameless and fawning entreaties, though some compliment it with the name of modesty and bashfulness, was the worst disgrace a great man could suffer. And he used to say that he always felt as if they who could deny nothing could not have behaved well in the flower of their youth.