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Cicero of Arpinum 106 – 43 BC
(●) The Roman lawyer who put Greek philosophy into Latin, and so gave the Western church the words it would think in. Marcus Tullius Cicero was not a professional philosopher, and he would have been embarrassed to be called one. He was a trial lawyer and a politician, the most famous public speaker in Rome, a man who spent his best years in courtrooms and in the senate house. The philosophy came late, mostly in the last two years of his life, and he wrote it in a hurry, in grief, with nothing else left to do. That accident of timing turned out to matter more than almost anything else he did. Greek philosophy had no Latin vocabulary. Consider what that means for a man sitting down to write: there was no Latin word for "quality," none for the branch of philosophy that studies right and wrong, and none for an atom, the uncuttable particle of matter that the Epicureans, the Greek school which explained the world as atoms moving in empty space, could not be discussed without. Cicero supplied the missing words, and he is straightforward enough to stop and say so as he goes. Qualitas he coined in the Academica for the Greek poiotes. Moralis he introduced in the opening lines of De Fato, because Latin had nothing for what the Greeks called ethos. Individuum, literally "indivisible," he made to carry the atom. Where an old Latin word would stretch to cover a Greek one he pressed it into service instead, so that providentia, plain foresight, the kind a farmer shows when he reads the sky before harvest, became the Latin for the Stoics’ pronoia. When Augustine, Ambrose, Jerome and Aquinas sat down to write Christian theology in Latin, they were writing in a language Cicero had built for the job. Here is the fact worth remembering. When Johann Fust and Peter Schoeffer, who inherited Gutenberg’s Mainz workshop, went looking for a pagan author worth the new machine’s time, they chose Cicero. His little book of moral advice for his son, De Officiis, printed at Mainz in 1465, is among the very first works of classical literature ever set in type, and its only rival for the honor is an undated Subiaco printing of De Oratore from the same year, which is Cicero as well. Fifteen hundred years after his death, the presses opened on him twice at once.
(●) 106 BC: He was born in a country town, with no ancestor who had ever sat in the Roman senate. Cicero was born on 3 January 106 BC at Arpinum, a hill town about sixty miles southeast of Rome, into a family of local landowners comfortable enough to matter at home and invisible in the capital. Rome had a word for a man in his position who climbed anyway: novus homo, a "new man," the first of his line to reach the consulship, the highest office in the state. It was not a compliment. The old families said it the way people today say "he came out of nowhere," and they said it about Cicero for the rest of his life. His father sent him and his younger brother Quintus to Rome to be educated, which was a considerable gamble with the family money. The boy turned out to have a gift that no amount of ancestry could buy. In a republic where careers were made by speaking in public, in the courts and before the assemblies, Cicero could speak better than anyone alive.
(●) 80 BC: He defended a man against the dictator Sulla’s favorite, won, and then left Rome for two years in Greece. Sextus Roscius was accused of murdering his own father. Behind the charge stood Chrysogonus, a freedman of the dictator Sulla, which is to say one of Sulla’s former slaves, freed by his master and still working inside his household and his influence. Chrysogonus had helped himself to the dead man’s estate and needed the son convicted to keep it. Nobody in Rome wanted the case. Cicero, twenty-six years old and largely unknown, took it and won an acquittal, and he did it by naming Chrysogonus in open court while Sulla was still in power. It is the speech that made him. Not long afterward he went east, to Athens and then to Rhodes, and stayed roughly from 79 to 77 BC. At Athens he studied philosophy under Antiochus of Ascalon, who then led Plato’s Academy, the school Plato had founded in that same city about three centuries earlier and which was still taking students. At Rhodes he studied rhetoric under Apollonius Molon, and there he also met Posidonius, the most learned Stoic of the age, a man of the Greek school that held that one rational order runs through the whole world and that a human mind is a share in it. Cicero himself says the trip was for his health, since his delivery was straining a thin body, and Plutarch reports the same. A later tradition adds that he judged it wise to be out of Italy while Sulla lived, which may be true and is not something Cicero ever admits. He came back with his voice repaired, his Greek fluent, and a set of philosophical friendships he would still be drawing on forty years later when he finally had time to write.
(●) 63 BC: As consul he broke a conspiracy against the state, and put five Roman citizens to death without a trial. In 63 BC Cicero reached the consulship, the office his family had never come near, and reached it in the first year he was legally old enough to hold it. Then Lucius Sergius Catilina, a bankrupt nobleman who had lost the same election, began raising an army in Etruria and planning arson and murder in the city. Cicero exposed him in a series of speeches, two in the senate and two before the people, that Roman schoolboys memorized for the next eighteen centuries, opening with the line every Latin student still meets: "When, O Catiline, do you mean to cease abusing our patience?" (Yonge’s translation). Catiline walked out of the senate and left Rome. Five of his associates were arrested inside the city with letters in their own handwriting, and on 5 December the senate debated what to do with them. Julius Caesar, then praetor-elect, which is to say he had just been chosen for the next year’s praetorship, the judicial office ranking immediately below the consulship, argued for imprisonment. Cato argued for death. Cicero had them strangled in the state prison that evening, on the senate’s authority and under an emergency decree, without the trial and the appeal to the people that Roman law guaranteed to a citizen. The city thanked him. Plutarch reports that Cato hailed him before the people as pater patriae, father of his country, and that he was the first Roman ever given the title. Cicero never stopped mentioning it, which his enemies never forgot, and he had handed them a weapon he could not take back: he had killed citizens without a trial, and everyone knew it.
(●) 58 BC: Those executions cost him everything, and he spent about eighteen months in exile while his house was pulled down. Publius Clodius Pulcher, a patrician turned popular politician with a private grudge against Cicero, became tribune in 58 BC. He had been born into the oldest layer of the Roman nobility and had made his career speaking for the crowd against it, and the office he now held, the tribunate, let him put a bill straight to the people’s assembly without going through the senate at all. He used it to push through a law condemning anyone who had put a Roman citizen to death without trial. No name was mentioned. None was needed. Cicero left Italy in March rather than stand and fight, and Clodius had a second law passed naming him, confiscating his property, and forbidding him fire and water within four hundred miles of Italy. That old formula sounds decorative and was not: to be interdicted from fire and water was a public notice that within those bounds no one might give the man so much as a roof or a meal. He went to Greece and fell apart. The letters he wrote from Thessalonica to his friend Atticus are the least guarded thing he ever produced, a famous man with nothing to do, ashamed of having run, telling his closest friend that he wished he were dead. His house on the Palatine was demolished and Clodius consecrated the ground to Liberty, dedicating the site to a goddess so that it belonged to her and not to any Roman, and so could never be built on again. The recall came by law on 4 August 57 BC, and he came up through Italy to something like a triumph, crowds turning out in the towns along the road. He got the site of his house back after arguing that the consecration was invalid before the college of priests, the board of religious officials who ruled on questions of sacred law. What he did not get back was his weight in politics. The men who actually held power now were Pompey, Crassus and Caesar, and for the next decade Cicero spoke when they let him.
(●) 49 BC: He chose the losing side in the civil war and was pardoned by the man he had opposed. When Caesar crossed the Rubicon in January 49 BC, bringing his army over the small river that marked the edge of his province, which no Roman general was permitted to cross under arms, Cicero spent months unable to decide, and the indecision is all over his letters. He liked Caesar personally and thought Pompey’s cause was badly led. He also thought that a republic, whatever its faults, was the thing he had spent his life serving. In June he sailed for Greece and joined Pompey’s camp, where by his own account he made himself unpopular by making jokes about the war he had come to fight. Pompey was destroyed at Pharsalus in August 48 BC and murdered in Egypt weeks later. Cicero refused command of the surviving fleet, went home to Brundisium, and waited nearly a year, not knowing whether he would be executed. Caesar landed in Italy in the autumn of 47, and Plutarch says that when he saw Cicero coming out ahead of the crowd to meet him, he got down, embraced him, and walked on beside him for a long stretch of road, talking. There was no punishment. The mercy was real and it was also the end of Cicero’s public life. A republic in which one man’s kindness decides whether you live is not a republic, and he knew it. He withdrew to his villas, divorced Terentia after roughly thirty years of marriage, briefly married a young ward named Publilia, and began, in his sixties, to write the books he had been putting off since Athens.
(●) 45 BC: His daughter died, and out of that grief came nearly all the philosophy he ever wrote. Tullia was about thirty-four and had been married three times, once widowed and twice divorced, and she died in February 45 BC not long after giving birth. Cicero had adored her past the point his friends thought seemly. He shut himself up at Astura, a villa on a wooded stretch of coast, and Atticus, alarmed, began sending him books. What followed has no real parallel in ancient literature. In something under two years, from the spring of 45 to the late autumn of 44, a grieving man in his sixties wrote a library: the Hortensius, an appeal to take up philosophy at all; the Academica on how much we can know; De Finibus on what the good life is; the Tusculan Disputations on death, pain and grief; De Natura Deorum on the gods; De Divinatione on prophecy and omens; De Fato on fate and freedom; the short books on old age and on friendship; and last of all De Officiis, written as a long letter of moral instruction to his son Marcus, who was studying at Athens and, by every indication, drinking. He also wrote a Consolatio for Tullia and planned a shrine to her, and he was rebuked for it by friends who thought a Roman gentleman should mourn more quietly. The Consolatio is lost. The rest is why anyone outside a classics department still reads him.
(●) 43 BC: He attacked Mark Antony in fourteen speeches, and was hunted down and killed for them. Caesar was murdered on 15 March 44 BC. Cicero was not in the plot, though he wished he had been, and for a few months the old republican found himself back at the center of events, the senior statesman everyone consulted. He decided that Mark Antony was the danger and that the nineteen-year-old Octavian, Caesar’s heir, could be used and then discarded. It was the worst judgment of his life. Between September 44 and April 43 he delivered or published fourteen speeches against Antony, which he called the Philippics after Demosthenes’ speeches against Philip of Macedon. They are savage, funny, and personal, and they are the last great performance of Roman republican oratory. Then in November 43 Octavian, Antony and Lepidus made their bargain, divided the state between them, and drew up lists of men to be killed. Each of the three gave up friends to have enemies. Octavian gave up Cicero. He was caught near Formiae on 7 December 43 BC, being carried toward the sea in a litter. Plutarch says he told his servants to set it down and stretched out his neck to the soldiers. Antony had the head and the hands cut off and nailed to the speaker’s platform in the Forum, where the hands had written the Philippics and the mouth had delivered them. Plutarch adds that the Romans who came to look shuddered, thinking they saw not Cicero’s face but the soul of Antony.
What He Taught
(T1) There is one true law, the same at Rome and at Athens, and no senate can repeal it. Every legal system has rules that can be changed by a vote. Speed limits, tax rates, the drinking age: a legislature raises its hands and the rule is different tomorrow. Now think about a rule that a vote could not touch. Suppose a parliament passed a law requiring parents to starve their children. You would not say the law was unwise. You would say it was not really a law at all, whatever the paperwork said. That reaction, which almost everyone has, is what Cicero was trying to account for. His answer is the doctrine we now call natural law: the claim that some moral rules are built into the way things are, discoverable by reason, binding on everyone, and not made by any assembly. He inherited the idea from the Stoics, the Greek school founded by Zeno of Citium, who taught that one rational order runs through the whole universe and that a human being shares in it by having a mind. What Cicero added was a courtroom lawyer’s precision about what follows. If such a law exists, then an unjust statute is a counterfeit; then a tyrant can be a criminal while breaking none of his own rules; then there is a standard the Roman senate itself can be measured against. He also saw what the doctrine requires. A law needs a lawgiver. In the passage that survives, Cicero does not stop at "nature" but names God as the author of this law, its announcer, and the judge who enforces it. That single move is why the Christian tradition could take the whole doctrine over almost unchanged.
(Q) "True law is right reason conformable to nature, universal, unchangeable, eternal, whose commands urge us to duty, and whose prohibitions restrain us from evil." Source: Cicero, De Re Publica III, ch. XXII (III.33) (Barham and Yonge translation). The passage goes on: "Neither the senate nor the people can give us any dispensation for not obeying this universal law of justice. It needs no other expositor and interpreter than our own conscience. It is not one thing at Rome, and another at Athens; one thing to-day, and another to-morrow; but in all times and nations this universal law must forever reign, eternal and imperishable. It is the sovereign master and emperor of all beings. God himself is its author, its promulgator, its enforcer." The speaker is Laelius, answering a case that the philosopher Carneades had made against justice: that what men call justice is no part of nature at all, only an arrangement communities keep up while it pays them, so that a people grown rich on conquest would have to hand everything back the moment it decided to be just. Most of De Re Publica was lost for centuries. These lines survive because the Christian writer Lactantius quoted them in full around AD 305 (T1).
(T2) A universe this orderly argues a mind behind it, exactly as a water clock does. In De Natura Deorum, "On the Nature of the Gods," Cicero does something unusual: he stages a debate and lets each side speak at full strength. An Epicurean argues that the gods exist but are wholly uninvolved. A Stoic named Balbus argues that the world is run by divine providence. An Academic named Cotta takes both of them apart. Academic is the name of a school rather than a compliment: Cotta belongs to Plato’s Academy in its later, skeptical phase, which held that certainty is past our reach and that the honest course is to hear every position, test it, and go with whichever comes out more probable. Cicero writes all three and gives no verdict of his own until the last line, which he keeps deliberately mild. Balbus makes the argument that would echo for two thousand years. Look at a water clock, he says, the ancient device that measured hours by a regulated flow of water into a marked vessel. Nobody who sees one thinks the hours are being counted by accident. Look at a ship under sail on the horizon; you conclude at once that somebody is steering. Then look at the sky, where the sun, moon and planets keep their courses so exactly that a man like Archimedes could build a bronze model to predict them. Why is the machine the work of a mind and the thing it copies not? This is the design argument in its Roman form, and it has an ancestry and a posterity. Plato had made a version of it, and eighteen centuries later William Paley would famously reach for a watch found on a heath. Cicero’s own position is more cautious than Balbus’s, since he wrote Cotta’s objections too and meant them to sting. What he leaves the reader is not a proof but a pressure: the universe looks like the sort of thing that was meant.
(Q) "When you see a dial or water-clock, you believe the hours are shown by art, and not by chance; and yet that you should imagine that the universe, which contains all arts and the artificers, can be void of reason and understanding?" Source: Cicero, De Natura Deorum II, ch. XXXIV (II.87) (Yonge translation). The Stoic Balbus is speaking, midway through the longest sustained defense of providence to survive from the ancient world. The full sentence begins with a picture and a ship: viewing a painting, you assume an artist; seeing a ship under sail, you assume a steersman (T2).
(T3) A person is his mind, and the body is the only part of him that dies. The most famous few pages Cicero ever wrote are a dream. At the end of De Re Publica he has the younger Scipio, a Roman general, fall asleep in Africa and be carried up by his dead grandfather to look down on the earth from among the stars. The empire he has been so proud of turns out to be a smudge on a small ball, and the fame he has been chasing cannot even cross an ocean, let alone outlast one turn of the heavens. Then comes the point of the vision. His grandfather tells him that the dead are the ones who are truly alive, having "escaped from the chains of the body as from a prison," and that what men call life on earth is a kind of death. Scipio, understandably, asks why he should not come at once, and his father Paulus, who has just come up to meet him, answers with a flat prohibition: no one may leave his post without the command of the God who assigned it, and to do so is desertion. Ancient readers noticed that. In a culture where a nobleman’s suicide could be an honorable exit, Cicero has the heavens forbid it. His argument for immortality is Plato’s, borrowed openly, and it is worth slowing down over. Nearly everything that moves is moved by something else. The cart is pulled by the horse, the ball is sent rolling by the boy’s foot, and neither of them has any motion of its own once the thing behind it lets go. Now imagine something that is not pushed from outside but is the source of its own motion. It never runs down, Cicero says, because the thing moving it is itself and it cannot desert itself, and since every other motion begins from it, nothing came earlier to set it going. What never began never ends. The mind is exactly such a thing: whatever is stirred only by a shove from outside is lifeless, and a living creature is moved from within, by a motion that is its own. Whatever moves itself never stops moving, and the mind moves itself; therefore the mind has no end. The reasoning has holes, and Cicero, who was a skeptic by training, admits elsewhere in the Tusculan Disputations that he finds the case persuasive without finding it certain. What is striking is how far the conclusion travels: your body is a garment, your mind is you, and the life you are living now is the short part.
(Q) "Consider your body only, not yourself, as mortal. For it is not your outward form which constitutes your being, but your mind; not that substance which is palpable to the senses, but your spiritual nature." Source: Cicero, De Re Publica VI (the Dream of Scipio), ch. XXIV (VI.26) (Barham and Yonge translation). The elder Scipio Africanus is speaking to his grandson. The sentence immediately following is the one Christian readers have always had to stop at: "Know, then, that you are a God." Cicero means that the mind rules the body as God rules the world, and the flattery is Stoic rather than blasphemous, but it marks a real distance from Scripture.
(T4) Nothing that is wrong is ever really to a man’s advantage. A grain merchant sails into a famine-struck city with a full cargo. He alone knows that a dozen more grain ships left port right behind him and will arrive within days, which will collapse the price. Must he tell the starving buyers, or may he sell high and say nothing? Cicero sets that case out in the third book of De Officiis and spends pages on it, because it is the exact place where two things people want come apart: the honorable thing, which he calls honestum, and the profitable thing, which he calls utile. Ordinary moral talk assumes these two really can conflict, and that being good sometimes costs you. Cicero denies it, and the denial is his central ethical claim. Wrongdoing damages the only part of a man that is properly his own, which is his character, and no cargo pays for that. So the appearance of a conflict is always a mistake in the accounting. The merchant should speak. The foundation underneath is a claim about what people are for. Quoting Plato, Cicero writes that we are not born for ourselves alone, but that our country claims a share of us and our friends a share; and that men are born for the sake of men, to help one another. Duty, in his hands, is not a set of restrictions on a life otherwise lived for yourself. It is what a life is made of. That is the book Ambrose would rewrite for Christian clergy four centuries later, keeping the structure and changing the ground.
(Q) "It is never expedient to do wrong, because wrong is always immoral; and it is always expedient to be good, because goodness is always moral." Source: Cicero, De Officiis III.64 (Miller translation). The conclusion of his long treatment of fraud in business and law. De Officiis was written for his son Marcus, then twenty-one and studying in Athens, and Cicero’s tone all through it is that of a father who suspects the letter will be skimmed (T4).
(T5) Superstition should be torn up by the roots, and religion left standing. Cicero held the office of augur, one of the Roman priests whose job was to read the will of the gods in the flight of birds, in lightning, and in other signs, and he thought the whole practice was nonsense. He said so in print, at length, in De Divinatione, and he still turned up for the ceremonies. Modern readers usually call that hypocrisy. He would have called it the difference between two things Latin already distinguished and English does not. Superstitio, in his usage, is fear: the anxious scanning of omens, the endless sacrifices offered by a parent terrified that a child will die first, the mind enslaved to signs. Religio is the opposite habit, the careful and reverent keeping of what has been handed down. In De Natura Deorum he traces the two words to their roots, superstitious from praying that one’s children might survive, religious from relegere, going over the sacred duties again with care. One word is a reproach; the other is a commendation. So his program is not to clear the gods out. He wants the fear gone and the reverence kept, and in the closing pages of De Divinatione he says why he cannot go further: the order of the heavens and the beauty of the world force him to confess that some excellent and eternal Being exists who deserves human reverence. It is an oddly modern position, and it is exactly the position the church fathers found useful. A man who has demolished the omens and is left standing in front of an eternal Being is a man who can be talked to.
(Q) "But I want it distinctly understood that the destruction of superstition does not mean the destruction of religion." Source: Cicero, De Divinatione II.148 (Falconer translation). From the last pages of the work, and the nearest thing in Cicero to a personal creed. He has just said that he hoped to do his countrymen a great service by tearing superstition up by the roots, and he ends: "Furthermore, the celestial order and the beauty of the universe compel me to confess that there is some excellent and eternal Being, who deserves the respect and homage of men" (T5).
(Q) "The force of reason in disputation is to be sought after rather than authority, since the authority of the teacher is often a disadvantage to those who are willing to learn." Source: Cicero, De Natura Deorum I, ch. V (I.10) (Yonge translation). Cicero is explaining why he will not tell the reader which of his three debaters he agrees with. He goes on to mock the Pythagoreans, the followers of Pythagoras, who settled arguments by saying "He himself has said it," meaning their founder. The habit of mind in this sentence is the one Christian readers would find both useful and dangerous: it made him a superb teacher of how to argue, and it left him unable to say he knew.
What Christian Thinkers Made of Him
(†) The Latin fathers learned to write philosophy by imitating him, and one of them saved his best page. Christianity arrived in the Latin West with no philosophical Latin of its own, and the first Christians who tried to argue with educated pagans reached for the only model available. Minucius Felix wrote the Octavius, a dialogue in which a Christian and a pagan argue on a beach at Ostia, in a form lifted straight from De Natura Deorum. Lactantius, tutor to the emperor Constantine’s son, wrote his Divine Institutes around AD 305 in prose so Ciceronian that the humanist Pico della Mirandola later called him the Christian Cicero. That imitation had a consequence nobody planned. Lactantius wanted to quote the finest thing a pagan had ever written about law, so he copied out the whole "true law" passage from De Re Publica (T1). The book itself then vanished. It was gone for more than a thousand years, until Angelo Mai, newly installed as a custodian of the Vatican Library, found much of it in 1819 hidden under a copy of Augustine’s commentary on the Psalms in a Vatican manuscript, the old text scraped off and written over. Book Three was among the parts still missing. The most quoted sentence Cicero ever wrote survives only because a Christian apologist admired it enough to copy it down. Ambrose of Milan went further and wrote a Christian replacement. His De Officiis Ministrorum, "On the Duties of the Clergy," follows Cicero’s De Officiis book by book and topic by topic, keeping the framework of duty and swapping the examples from Roman generals to Abraham, Joseph and David (T4).
(†) A lost book of his turned Augustine toward God at nineteen, and a remembered one gave Jerome a nightmare. In about AD 373 a nineteen-year-old student of rhetoric at Carthage picked up a book of Cicero’s because it was on the syllabus and would improve his prose style. It was the Hortensius, the appeal to philosophy Cicero had written in his grief after Tullia died. Augustine describes what happened next in the Confessions: "This book, in truth, changed my affections, and turned my prayers to Yourself, O Lord, and made me have other hopes and desires. Worthless suddenly became every vain hope to me; and, with an incredible warmth of heart, I yearned for an immortality of wisdom" (Confessions III.4.7, Pilkington translation). He is careful about what the book did and did not do. It gave him a hunger for wisdom itself rather than for one school’s version of it, and that hunger led him eventually to Scripture. What checked his delight, he says in the same passage, was that the name of Christ was not in it, and that name had been in his heart since his mother taught it to him. Thirteen years of wandering followed before Milan: first the Manichees, a sect that accounted for evil by making it an eternal power at war with God, then a season of Academic skepticism, the habit of doubting whether anything at all can be known for certain, then the Neoplatonists, the late followers of Plato whose books were what finally let him conceive of God as something other than an enormous body spread out through space. The Hortensius is now lost apart from fragments quoted by later writers, most of them by Augustine himself, which is a strange kind of debt: the book that made him is preserved chiefly in the man it made. Jerome, who was producing the Latin Bible at roughly the same time, had the opposite reaction and a worse night. He tells Eustochium, the young Roman woman he was directing in the ascetic life, that he fasted and then read Cicero for pleasure, and dreamed he was dragged before the judgment seat and asked what he was. He answered that he was a Christian, and the judge said he lied: "You are a follower of Cicero and not of Christ" (Letter 22.30, Fremantle translation). He woke and swore off pagan books, an oath he kept about as well as most such oaths, since his letters go on quoting Cicero for another forty years.
(†) His true law became the church’s natural law, and then the West’s language of rights. Paul had already said, writing to Rome within a century of Cicero’s death, that Gentiles who never received the Law "instinctively perform the requirements of the Law" and so "they show that the work of the law is written on their hearts, while their conscience also bears witness" (Romans 2:14–15). Cicero is the best pagan evidence for that claim anyone could ask for: a man with no Scripture, arguing from reason alone, who arrived at a universal moral law with God as its author (T1). Thomas Aquinas built the medieval account of law on exactly this footing, distinguishing eternal law in the mind of God, natural law as the rational creature’s share in it, and human law as what legislatures actually pass. He quotes Cicero repeatedly in the Summa Theologiae, chiefly on justice and on the parts of the virtues, and though his own definition of natural law comes down to him through Augustine and Aristotle, the conviction underneath it is the one Cicero argued for: a statute at odds with right reason is not really a law. From there the doctrine travels: to Hugo Grotius and the beginnings of international law, to John Locke, and into the American Declaration of Independence with its self-evident truths and unalienable rights. The practical value is easy to miss because it is so familiar. When a Christian argues today that a law permitting some cruelty is unjust, and expects the argument to land on someone who does not share his Bible, he is using a tool Cicero shaped. There is a standard above the statute book, and the person you are arguing with already knows it.
(†) Where the gospel parts company with him: glory is not grace, and "you are a God" is not the good news. The church kept Cicero close, so the disagreements are worth stating plainly rather than smoothing over. - What the afterlife is for. In the Dream of Scipio the heavens are a reward for statesmen who served their country well, and the reasoning is frankly aristocratic: do great public deeds, earn a place among the stars. Scripture does not hand out eternity for public service. "For by grace you have been saved through faith. And this is not your own doing; it is the gift of God, not a result of works, so that no one may boast" (Ephesians 2:8–9). A fisherman and a consul arrive by the same door. - What a human being is. "Know, then, that you are a God" is a compliment Cicero pays the mind, and Scripture reserves that sentence for the serpent: "you will be like God, knowing good and evil" (Genesis 3:5). The Christian claim runs the other way. God did not tell men they were divine; He "emptied himself, by taking the form of a servant, being born in the likeness of men" (Philippians 2:7). - The body. Cicero, following Plato, calls the body a prison and death a release, and hopes for a soul flying free of it. The gospel promises the body back, raised and remade, which is why Paul’s Athenian audience laughed (Acts 17:32). - Certainty. Cicero was an Academic skeptic by training and said so proudly: probability was as far as he would go, and he refused to tell his readers what he himself believed. That habit made him an honest inquirer and left him with nothing to die for except his country. The apostles claimed to know, and gave the reason: not a clever inference, but a man they had watched eat after He was buried. - Glory. His besetting sin, by the testimony of everyone who knew him and of his own letters, was wanting to be admired. He could not stop mentioning his consulship. It is not a small flaw in a moral teacher, and Paul’s answer to the whole ancient project of earning honor by wisdom is blunt: "since, in the wisdom of God, the world did not know God through wisdom, it pleased God through the folly of what we preach to save those who believe" (1 Corinthians 1:21). None of this made the church put him down. Augustine, who owed him his first turn toward God, went on arguing with him for the rest of his life, and The City of God takes De Re Publica seriously enough to answer it at length. That is the right posture toward Cicero: he saw the law and could not find the lawgiver’s face, and he wrote the sentences the people who found it would use.