Marcus Tullius Cicero

Cicero was a lawyer and a consul before he was a philosopher, and it is the lawyer-statesman who matters most: he took the philosophy of Greece and poured it into Latin, and in doing so built the vocabulary the West still thinks with. When you say moral, quality, essence, humane, you are using words Cicero coined or fixed to carry Greek ideas into a language that had no room for them. Philosophy entered the Western bloodstream in his prose.

His deepest bequest is a single sentence. In On the Republic he wrote that true law is right reason in agreement with nature – universal, unchanging, binding on every nation and every age, a law no senate can repeal and no tyrant annul. Every later declaration of rights is a footnote to that line. On Duties, his manual of the honourable life, was for centuries the most printed book in Europe after the Bible; and from it, and from his praise of humanitas – the cultivation that makes a person fully human – the Renaissance took its very name for itself.

He gave his life to a republic that was dying under the weight of strongmen. He defended the rule of law against Caesar's heirs, and when Mark Antony's proscription lists went up, Cicero's name was on them. Soldiers caught him on the road; he leaned out of his litter and bared his throat. His head and his hands – the hands that had written the Philippics against Antony – were nailed to the Rostra in the Forum where he had once spoken. He belongs to the site's long line of the murdered: Socrates, Cicero, Boethius, Stein. A young man named Augustine would later open Cicero's lost Hortensius, catch fire with the love of wisdom, and never recover – which is how a pagan consul lit the match under Christian philosophy.