His influence on the Latin language was so immense that the subsequent history of prose, not only in Latin but in European languages up to the 19th century, was said to be either a reaction against or a return to his style. According to Michael Grant, "the influence of Cicero upon the history of European literature and ideas greatly exceeds that of any other prose writer in any language". Cicero introduced the Romans to the chief schools of Greek philosophy and created a Latin philosophical vocabulary (with neologisms such as evidentia, humanitas, qualitas, quantitas, and essentia) distinguishing himself as a translator and philosopher.
Though he was an accomplished orator and successful lawyer, Cicero believed his political career was his most important achievement. It was during his consulship that the second Catilinarian conspiracy attempted to overthrow the government through an attack on the city by outside forces, and Cicero suppressed the revolt by executing five conspirators without due process. During the chaotic latter half of the 1st century BC marked by civil wars and the dictatorship of Gaius Julius Caesar, Cicero championed a return to the traditional republican government. Following Julius Caesar's death, Cicero became an enemy of Mark Antony in the ensuing power struggle, attacking him in a series of speeches. He was proscripted as an enemy of the state by the Second Triumvirate and consequently executed by soldiers operating on their behalf in 43 BC after having been intercepted during attempted flight from the Italian peninsula. His severed hands and head were then, as a final revenge of Mark Antony, displayed in the Roman Forum.
Petrarch's rediscovery of Cicero's letters is often credited for initiating the 14th-century Renaissance in public affairs, humanism, and classical Roman culture. According to Polish historian Tadeusz Zieliński, "the Renaissance was above all things a revival of Cicero, and only after him and through him of the rest of Classical antiquity." The peak of Cicero's authority and prestige came during the 18th-century Enlightenment, and his impact on leading Enlightenment thinkers and political theorists such as John Locke, David Hume, Montesquieu and Edmund Burke was substantial. His works rank among the most influential in European culture, and today still constitute one of the most important bodies of primary material for the writing and revision of Roman history, especially the last days of the Roman Republic.
Cicero was born in 106 BC in Arpinum, a hill town 100 kilometers (62 mi) southeast of Rome. His father was a well-to-do member of the equestrian order and possessed good connections in Rome. However, being a semi-invalid, he could not enter public life and studied extensively to compensate. Although little is known about Cicero's mother, Helvia, it was common for the wives of important Roman citizens to be responsible for the management of the household. Cicero's brother Quintus wrote in a letter that she was a thrifty housewife.
Cicero's cognomen, or personal surname, comes from the Latin for chickpea, cicer. Plutarch explains that the name was originally given to one of Cicero's ancestors who had a cleft in the tip of his nose resembling a chickpea. However, it is more likely that Cicero's ancestors prospered through the cultivation and sale of chickpeas. Romans often chose down-to-earth personal surnames. The famous family names of Fabius, Lentulus, and Piso come from the Latin names of beans, lentils, and peas, respectively. Plutarch writes that Cicero was urged to change this deprecatory name when he entered politics, but refused, saying that he would make Cicero more glorious than Scaurus ("Swollen-ankled") and Catulus ("Puppy").
During this period in Roman history, "cultured" meant being able to speak both Latin and Greek. Cicero was therefore educated in the teachings of the ancient Greek philosophers, poets and historians; he obtained much of his understanding of the theory and practice of rhetoric from the Greek poet Archias and from the Greek rhetorician Apollonius. Cicero used his knowledge of Greek to translate many of the theoretical concepts of Greek philosophy into Latin, thus translating Greek philosophical works for a larger audience. It was precisely his broad education that tied him to the traditional Roman elite.
According to Plutarch, Cicero was an extremely talented student, whose learning attracted attention from all over Rome, affording him the opportunity to study Roman law under Quintus Mucius Scaevola. Cicero's fellow students were Gaius Marius Minor, Servius Sulpicius Rufus (who became a famous lawyer, one of the few whom Cicero considered superior to himself in legal matters), and Titus Pomponius. The latter two became Cicero's friends for life, and Pomponius (who later received the nickname "Atticus", and whose sister married Cicero's brother) would become, in Cicero's own words, "as a second brother", with both maintaining a lifelong correspondence.
Cicero wanted to pursue a public career in politics along the steps of the Cursus honorum. In 90 BC–88 BC, he served both Gnaeus Pompeius Strabo and Lucius Cornelius Sulla as they campaigned in the Social War, though he had no taste for military life, being an intellectual first and foremost. Cicero started his career as a lawyer around 83–81 BC. His first major case, of which a written record is still extant, was his 80 BC defense of Sextus Roscius on the charge of patricide. Taking this case was a courageous move for Cicero; patricide was considered an appalling crime, and the people whom Cicero accused of the murder, the most notorious being Chrysogonus, were favorites of Sulla. At this time it would have been easy for Sulla to have the unknown Cicero murdered. Cicero's defense was an indirect challenge to the dictator Sulla, and on the strength of his case, Roscius was acquitted.
Cicero’s case was divided into three parts. The first part detailed exactly the charge brought by Ericius. Cicero explained how a rustic son of a farmer, who lives off the pleasures of his own land, would not have gained anything from committing patricide because he would have eventually inherited his father's land anyway. The second part concerned the boldness and greed of two of the accusers, Magnus and Capito. Cicero told the jury that they were the more likely perpetrators of murder because the two were greedy, both for conspiring together against a fellow kinsman and, in particular, Magnus, for his boldness and for being unashamed to appear in court to support the false charges. The third part explained that Chrysogonus had immense political power, and the accusation was successfully made due to that power. Even though Chrysogonus may not have been what Cicero said he was, through rhetoric Cicero successfully made him appear to be a foreign freed man who prospered by devious means in the aftermath of the civil war. Cicero surmised that it showed what kind of a person he was and that something like murder was not beneath him.
Cicero's interest in philosophy figured heavily in his later career and led to him providing a comprehensive account of Greek philosophy for a Roman audience, including creating a philosophical vocabulary in Latin. In 87 BC, Philo of Larissa, the head of the Academy that was founded by Plato in Athens about 300 years earlier, arrived in Rome. Cicero, "inspired by an extraordinary zeal for philosophy", sat enthusiastically at his feet and absorbed Plato's philosophy. Cicero said of Plato's Dialogues, that if Zeus were to speak, he would use their language.
In 79 BC, Cicero left for Greece, Asia Minor and Rhodes. This was perhaps to avoid the potential wrath of Sulla, though Cicero himself says it was to hone his skills and improve his physical fitness. In Athens he studied philosophy with Antiochus of Ascalon, the 'Old Academic' and initiator of Middle Platonism. In Asia Minor, he met the leading orators of the region and continued to study with them. Cicero then journeyed to Rhodes to meet his former teacher, Apollonius Molon, who had previously taught him in Rome. Molon helped Cicero hone the excesses in his style, as well as train his body and lungs for the demands of public speaking. Charting a middle path between the competing Attic and Asiatic styles, Cicero would ultimately become considered second only to Demosthenes among history's orators.
Cicero married Terentia probably at the age of 27, in 79 BC. According to the upper class mores of the day it was a marriage of convenience, but lasted harmoniously for nearly 30 years. Terentia's family was wealthy, probably the plebeian noble house of Terenti Varrones, thus meeting the needs of Cicero's political ambitions in both economic and social terms. She had a half-sister named Fabia, who as a child had become a Vestal Virgin, a very great honour. Terentia was a strong willed woman and (citing Plutarch) "she took more interest in her husband's political career than she allowed him to take in household affairs."
In the 50s BC, Cicero's letters to Terentia became shorter and colder. He complained to his friends that Terentia had betrayed him but did not specify in which sense. Perhaps the marriage simply could not outlast the strain of the political upheaval in Rome, Cicero's involvement in it, and various other disputes between the two. The divorce appears to have taken place in 51 BC or shortly before. In 46 or 45 BC, Cicero married a young girl, Publilia, who had been his ward. It is thought that Cicero needed her money, particularly after having to repay the dowry of Terentia, who came from a wealthy family. This marriage did not last long.
Although his marriage to Terentia was one of convenience, it is commonly known that Cicero held great love for his daughter Tullia. When she suddenly became ill in February 45 BC and died after having seemingly recovered from giving birth to a son in January, Cicero was stunned. "I have lost the one thing that bound me to life" he wrote to Atticus. Atticus told him to come for a visit during the first weeks of his bereavement, so that he could comfort him when his pain was at its greatest. In Atticus's large library, Cicero read everything that the Greek philosophers had written about overcoming grief, "but my sorrow defeats all consolation." Caesar and Brutus as well as Servius Sulpicius Rufus sent him letters of condolence.
Cicero hoped that his son Marcus would become a philosopher like him, but Marcus himself wished for a military career. He joined the army of Pompey in 49 BC and after Pompey's defeat at Pharsalus 48 BC, he was pardoned by Caesar. Cicero sent him to Athens to study as a disciple of the peripatetic philosopher Kratippos in 48 BC, but he used this absence from "his father's vigilant eye" to "eat, drink and be merry." After Cicero's murder he joined the army of the Liberatores but was later pardoned by Augustus. Augustus' bad conscience for not having objected to Cicero's being put on the proscription list during the Second Triumvirate led him to aid considerably Marcus Minor's career. He became an augur, and was nominated consul in 30 BC together with Augustus. As such, he was responsible for revoking the honors of Mark Antony, who was responsible for the proscription, and could in this way take revenge. Later he was appointed proconsul of Syria and the province of Asia.
His first office was as one of the twenty annual quaestors, a training post for serious public administration in a diversity of areas, but with a traditional emphasis on administration and rigorous accounting of public monies under the guidance of a senior magistrate or provincial commander. Cicero served as quaestor in western Sicily in 75 BC and demonstrated honesty and integrity in his dealings with the inhabitants. As a result, the grateful Sicilians asked Cicero to prosecute Gaius Verres, a governor of Sicily, who had badly plundered the province. His prosecution of Gaius Verres was a great forensic success for Cicero. Governor Gaius Verres hired the prominent lawyer of a noble family Quintus Hortensius Hortalus. After a lengthy period in Sicily collecting testimonials and evidence and persuading witnesses to come forward, Cicero returned to Rome and won the case in a series of dramatic court battles. His unique style of oratory set him apart from the flamboyant Hortensius. On the conclusion of this case, Cicero came to be considered the greatest orator in Rome. The view that Cicero may have taken the case for reasons of his own is viable. Hortensius was, at this point, known as the best lawyer in Rome; to beat him would guarantee much success and the prestige that Cicero needed to start his career. Cicero's oratorical skill is shown in his character assassination of Verres and various other techniques of persuasion used on the jury. One such example is found in the speech Against Verres I, where he states "with you on this bench, gentlemen, with Marcus Acilius Glabrio as your president, I do not understand what Verres can hope to achieve". Oratory was considered a great art in ancient Rome and an important tool for disseminating knowledge and promoting oneself in elections, in part because there were no regular newspapers or mass media. Cicero was neither a patrician nor a plebeian noble; his rise to political office despite his relatively humble origins has traditionally been attributed to his brilliance as an orator.
Cicero grew up in a time of civil unrest and war. Sulla's victory in the first of a series of civil wars led to a new constitutional framework that undermined libertas (liberty), the fundamental value of the Roman Republic. Nonetheless, Sulla's reforms strengthened the position of the equestrian class, contributing to that class's growing political power. Cicero was both an Italian eques and a novus homo, but more importantly he was a Roman constitutionalist. His social class and loyalty to the Republic ensured that he would "command the support and confidence of the people as well as the Italian middle classes". The optimates faction never truly accepted Cicero; and this undermined his efforts to reform the Republic while preserving the constitution. Nevertheless, he successfully ascended the cursus honorum, holding each magistracy at or near the youngest possible age: quaestor in 75 BC (age 31), aedile in 69 BC (age 37), and praetor in 66 BC (age 40), when he served as president of the "Reclamation" (or extortion) Court. He was then elected consul at age 43.
Cicero was elected consul for the year 63 BC. His co-consul for the year, Gaius Antonius Hybrida, played a minor role. During his year in office, he thwarted a conspiracy centered on assassinating him and overthrowing the Roman Republic with the help of foreign armed forces, led by Lucius Sergius Catilina. Cicero procured a senatus consultum ultimum (a declaration of martial law) and drove Catiline from the city with four vehement speeches (the Catiline Orations), which to this day remain outstanding examples of his rhetorical style. The Orations listed Catiline and his followers' debaucheries, and denounced Catiline's senatorial sympathizers as roguish and dissolute debtors clinging to Catiline as a final and desperate hope. Cicero demanded that Catiline and his followers leave the city. At the conclusion of his first speech, Catiline hurriedly left the Senate, (which was being held in the Temple of Jupiter Stator). In his following speeches, Cicero did not directly address Catiline. He delivered the second and third orations before the people, and the last one again before the Senate. By these speeches, Cicero wanted to prepare the Senate for the worst possible case; he also delivered more evidence against Catiline.
Catiline fled and left behind his followers to start the revolution from within while Catiline assaulted the city with an army of "moral bankrupts and honest fanatics". Catiline had attempted to involve the Allobroges, a tribe of Transalpine Gaul, in their plot, but Cicero, working with the Gauls, was able to seize letters that incriminated the five conspirators and forced them to confess in front of the Senate.
The Senate then deliberated upon the conspirators' punishment. As it was the dominant advisory body to the various legislative assemblies rather than a judicial body, there were limits to its power; however, martial law was in effect, and it was feared that simple house arrest or exile – the standard options – would not remove the threat to the state. At first Decimus Silanus spoke for the "extreme penalty"; many were swayed by Julius Caesar, who decried the precedent it would set and argued in favor of life imprisonment in various Italian towns. Cato the Younger rose in defence of the death penalty and the entire Senate finally agreed on the matter. Cicero had the conspirators taken to the Tullianum, the notorious Roman prison, where they were strangled. Cicero himself accompanied the former consul Publius Cornelius Lentulus Sura, one of the conspirators, to the Tullianum. Cicero received the honorific "Pater Patriae" for his efforts to suppress the conspiracy, but lived thereafter in fear of trial or exile for having put Roman citizens to death without trial.
After the conspirators were put to death, Cicero was proud of his accomplishment. Some of his political enemies argued that though the act gained Cicero popularity, he exaggerated the extent of his success. He overestimated his popularity again several years later after being exiled from Italy and then allowed back from exile. At this time, he claimed that the Republic would be restored along with him.
In 60 BC, Julius Caesar invited Cicero to be the fourth member of his existing partnership with Pompey and Marcus Licinius Crassus, an assembly that would eventually be called the First Triumvirate. Cicero refused the invitation because he suspected it would undermine the Republic.
In 58 BC, Publius Clodius Pulcher, the tribune of the plebs, introduced a law (the Leges Clodiae) threatening exile to anyone who executed a Roman citizen without a trial. Cicero, having executed members of the Catiline Conspiracy four years previously without formal trial, and having had a public falling out with Clodius, was clearly the intended target of the law. Cicero argued that the senatus consultum ultimum indemnified him from punishment, and he attempted to gain the support of the senators and consuls, especially of Pompey. When help was not forthcoming, he went into exile. He arrived at Thessalonica, on May 23, 58 BC. Cicero's exile caused him to fall into depression. He wrote to Atticus: "Your pleas have prevented me from committing suicide. But what is there to live for? Don't blame me for complaining. My afflictions surpass any you ever heard of earlier". After the intervention of recently elected tribune Titus Annius Milo, the senate voted in favor of recalling Cicero from exile. Clodius cast the single vote against the decree. Cicero returned to Italy on August 5, 57 BC, landing at Brundisium. He was greeted by a cheering crowd, and, to his delight, his beloved daughter Tullia.
Cicero tried to re-enter politics, but his attack on a bill of Caesar's proved unsuccessful. The conference at Luca in 56 BC forced Cicero to recant and support the triumvirate. After this, a cowed Cicero concentrated on his literary works. It is uncertain whether he was directly involved in politics for the following few years. He reluctantly accepted a promagistracy in Cilicia for 51 BC, because there were few other eligible governors available as a result of a legislative requirement enacted by Pompey in 52 BC, specifying an interval of five years between a consulship or praetorship and a provincial command. He served as proconsul of Cilicia from May 51 to November 50 BC. He was given instructions to keep nearby Cappadocia loyal to the King, Ariobarzanes III, which he achieved ‘satisfactorily without war.’ Rome’s defeat by the Parthians and an uprising in Syria caused disquiet in Cilicia. Cicero maintained calm though his mild government. He discovered that much of public property had been embezzled and restored it. This made the cities better off. He retained the civil rights of, and did not impose penalties on, the men who gave the property back. Cicero defeated some robbers who were based on Mount Amanus and his soldiers hailed him as imperator. On his way back to Rome he stopped in Rhodes. He then spent some time in Athens, where he caught up with an old friend from his previous stay there and met men of great learning.
The struggle between Pompey and Julius Caesar grew more intense in 50 BC. Cicero favoured Pompey, seeing him as a defender of the senate and Republican tradition, but at that time avoided openly alienating Caesar. When Caesar invaded Italy in 49 BC, Cicero fled Rome. Caesar, seeking the legitimacy of an endorsement by a senior senator, courted Cicero's favour, but even so Cicero slipped out of Italy and traveled to Dyrrachium (Epidamnos), Illyria, where Pompey's staff was situated. Cicero traveled with the Pompeian forces to Pharsalus in 48 BC, though he was quickly losing faith in the competence and righteousness of the Pompeian side. Eventually, he provoked the hostility of his fellow senator Cato, who told him that he would have been of more use to the cause of the optimates if he had stayed in Rome. After Caesar's victory at the Battle of Pharsalus on August 9, Cicero returned to Rome only very cautiously. Caesar pardoned him and Cicero tried to adjust to the situation and maintain his political work, hoping that Caesar might revive the Republic and its institutions.
In a letter to Varro on c. April 20, 46 BC, Cicero outlined his strategy under Caesar's dictatorship. Cicero, however, was taken completely by surprise when the Liberatores assassinated Caesar on the ides of March, 44 BC. Cicero was not included in the conspiracy, even though the conspirators were sure of his sympathy. Marcus Junius Brutus called out Cicero's name, asking him to restore the republic when he lifted his bloodstained dagger after the assassination. A letter Cicero wrote in February 43 BC to Trebonius, one of the conspirators, began, "How I could wish that you had invited me to that most glorious banquet on the Ides of March"! Cicero became a popular leader during the period of instability following the assassination. He had no respect for Mark Antony, who was scheming to take revenge upon Caesar's murderers. In exchange for amnesty for the assassins, he arranged for the Senate to agree not to declare Caesar to have been a tyrant, which allowed the Caesarians to have lawful support and kept Caesar's reforms and policies intact.
Cicero and Antony now became the two leading men in Rome: Cicero as spokesman for the Senate; Antony as consul, leader of the Caesarian faction, and unofficial executor of Caesar's public will. Relations between the two, never friendly, worsened after Cicero claimed that Antony was taking liberties in interpreting Caesar's wishes and intentions. Octavian was Caesar's adopted son and heir; after he returned to Italy, Cicero began to play him against Antony. He praised Octavian, declaring he would not make the same mistakes as his father. He attacked Antony in a series of speeches he called the Philippics, after Demosthenes's denunciations of Philip II of Macedon. At the time Cicero's popularity as a public figure was unrivalled.
Cicero supported Decimus Junius Brutus Albinus as governor of Cisalpine Gaul (Gallia Cisalpina) and urged the Senate to name Antony an enemy of the state. The speech of Lucius Piso, Caesar's father-in-law, delayed proceedings against Antony. Antony was later declared an enemy of the state when he refused to lift the siege of Mutina, which was in the hands of Decimus Brutus. Cicero’s plan to drive out Antony failed. Antony and Octavian reconciled and allied with Lepidus to form the Second Triumvirate after the successive battles of Forum Gallorum and Mutina. The Triumvirate began proscribing their enemies and potential rivals immediately after legislating the alliance into official existence for a term of five years with consular imperium. Cicero and all of his contacts and supporters were numbered among the enemies of the state, and reportedly, Octavian argued for two days against Cicero being added to the list.
Cicero was one of the most viciously and doggedly hunted among the proscribed. He was viewed with sympathy by a large segment of the public and many people refused to report that they had seen him. He was caught December 7, 43 BC leaving his villa in Formiae in a litter going to the seaside where he hoped to embark on a ship destined for Macedonia. When his killers – Herennius (a centurion) and Popilius (a tribune) – arrived, Cicero's own slaves said they had not seen him, but he was given away by Philologus, a freed slave of his brother Quintus Cicero.
Cicero's last words are said to have been, "There is nothing proper about what you are doing, soldier, but do try to kill me properly." He bowed to his captors, leaning his head out of the litter in a gladiatorial gesture to ease the task. By baring his neck and throat to the soldiers, he was indicating that he wouldn't resist. According to Plutarch, Herennius first slew him, then cut off his head. On Antony's instructions his hands, which had penned the Philippics against Antony, were cut off as well; these were nailed along with his head on the Rostra in the Forum Romanum according to the tradition of Marius and Sulla, both of whom had displayed the heads of their enemies in the Forum. Cicero was the only victim of the proscriptions who was displayed in that manner. According to Cassius Dio (in a story often mistakenly attributed to Plutarch), Antony's wife Fulvia took Cicero's head, pulled out his tongue, and jabbed it repeatedly with her hairpin in final revenge against Cicero's power of speech.
Cicero's son, Marcus Tullius Cicero Minor, during his year as a consul in 30 BC, avenged his father's death, to a certain extent, when he announced to the Senate Mark Antony's naval defeat at Actium in 31 BC by Octavian and his capable commander-in-chief, Agrippa.
Octavian is reported to have praised Cicero as a patriot and a scholar of meaning in later times, within the circle of his family. However, it was Octavian's acquiescence that had allowed Cicero to be killed, as Cicero was proscribed by the new triumvirate.
Cicero's career as a statesman was marked by inconsistencies and a tendency to shift his position in response to changes in the political climate. His indecision may be attributed to his sensitive and impressionable personality; he was prone to overreaction in the face of political and private change. "Would that he had been able to endure prosperity with greater self-control, and adversity with more fortitude!" wrote C. Asinius Pollio, a contemporary Roman statesman and historian.
Cicero has been traditionally considered the master of Latin prose, with Quintilian declaring that Cicero was "not the name of a man, but of eloquence itself." The English words Ciceronian (meaning "eloquent") and cicerone (meaning "local guide") derive from his name. He is credited with transforming Latin from a modest utilitarian language into a versatile literary medium capable of expressing abstract and complicated thoughts with clarity. Julius Caesar praised Cicero's achievement by saying "it is more important to have greatly extended the frontiers of the Roman spirit (ingenium) than the frontiers of the Roman empire". According to John William Mackail, "Cicero's unique and imperishable glory is that he created the language of the civilized world, and used that language to create a style which nineteen centuries have not replaced, and in some respects have hardly altered."
Cicero was also an energetic writer with an interest in a wide variety of subjects, in keeping with the Hellenistic philosophical and rhetorical traditions in which he was trained. The quality and ready accessibility of Ciceronian texts favored very wide distribution and inclusion in teaching curricula, as suggested by a graffito at Pompeii, admonishing: "You will like Cicero, or you will be whipped". Cicero was greatly admired by influential Church Fathers such as Augustine of Hippo, who credited Cicero's lost Hortensius for his eventual conversion to Christianity, and St. Jerome, who had a feverish vision in which he was accused of being "follower of Cicero and not of Christ" before the judgment seat. This influence further increased after the Early Middle Ages in Europe, which more of his writings survived than any other Latin author. Medieval philosophers were influenced by Cicero's writings on natural law and innate rights.
Petrarch's rediscovery of Cicero's letters provided the impetus for searches for ancient Greek and Latin writings scattered throughout European monasteries, and the subsequent rediscovery of classical antiquity led to the Renaissance. Subsequently, Cicero became synonymous with classical Latin to such an extent that a number of humanist scholars began to assert that no Latin word or phrase should be used unless it appeared in Cicero's works, a stance criticized by Erasmus.
His voluminous correspondence, much of it addressed to his friend Atticus, has been especially influential, introducing the art of refined letter writing to European culture. Cornelius Nepos, the 1st century BC biographer of Atticus, remarked that Cicero's letters contained such a wealth of detail "concerning the inclinations of leading men, the faults of the generals, and the revolutions in the government" that their reader had little need for a history of the period.
Among Cicero's admirers were Desiderius Erasmus, Martin Luther, and John Locke. Following the invention of Johannes Gutenberg's printing press, De Officiis was the second book printed in Europe, after the Gutenberg Bible. Scholars note Cicero's influence on the rebirth of religious toleration in the 17th century.
While Cicero the humanist deeply influenced the culture of the Renaissance, Cicero the republican inspired the Founding Fathers of the United States and the revolutionaries of the French Revolution. John Adams said, "As all the ages of the world have not produced a greater statesman and philosopher united than Cicero, his authority should have great weight." Jefferson names Cicero as one of a handful of major figures who contributed to a tradition “of public right” that informed his draft of the Declaration of Independence and shaped American understandings of "the common sense" basis for the right of revolution. Camille Desmoulins said of the French republicans in 1789 that they were "mostly young people who, nourished by the reading of Cicero at school, had become passionate enthusiasts for liberty".
Jim Powell starts his book on the history of liberty with the sentence: "Marcus Tullius Cicero expressed principles that became the bedrock of liberty in the modern world."
Likewise, no other ancient personality has inspired as much venomous dislike as Cicero, especially in more modern times. His commitment to the values of the Republic accommodated a hatred of the poor and persistent opposition to the advocates and mechanisms of popular representation. Friedrich Engels referred to him as "the most contemptible scoundrel in history" for upholding republican "democracy" while at the same time denouncing land and class reforms. Cicero has faced criticism for exaggerating the democratic qualities of republican Rome, and for defending the Roman oligarchy against the popular reforms of Caesar. Michael Parenti admits Cicero's abilities as an orator, but finds him a vain, pompous and hypocritical personality who, when it suited him, could show public support for popular causes that he privately despised. Parenti presents Cicero's prosecution of the Catiline conspiracy as legally flawed at least, and possibly unlawful.
Cicero also had an influence on modern astronomy. Nicolaus Copernicus, searching for ancient views on earth motion, said that he "first ... found in Cicero that Hicetas supposed the earth to move."
Cicero was declared a righteous pagan by the Early Church, and therefore many of his works were deemed worthy of preservation. The Bogomils considered him a rare exception of a pagan saint. Subsequent Roman and medieval Christian writers quoted liberally from his works De Re Publica (On the Commonwealth) and De Legibus (On the Laws), and much of his work has been recreated from these surviving fragments. Cicero also articulated an early, abstract conceptualization of rights, based on ancient law and custom. Of Cicero's books, six on rhetoric have survived, as well as parts of eight on philosophy. Of his speeches, 88 were recorded, but only 58 survive.(81 BC) Pro Quinctio (In Defense of Quinctius)
(80 BC) Pro Roscio Amerino (In Defense of Roscius of Ameria)
(70 BC) In Verrem (Against Verres)
(69 BC) Pro Fonteio (In Defense of Fonteius)
(69 BC) Pro Caecina (In Defense of Caecina)
(66 BC) Pro Cluentio (In Defense of Cluentius)
(66 BC) De Imperio Gnaei Pompei or De Lege Manilia (On the Command of Gnaeus Pompey)
(63 BC) De Lege Agraria (On the Agrarian Law proposed by Servilius Rullus)
(63 BC) In Catilinam (Against Catiline)
(63 BC) Pro Rabirio Perduellionis Reo (In Defense of Rabirius)
(62 BC) Pro Sulla (In Defense of Sulla)
(62 BC) Pro Archia Poeta (In Defense of Archias the Poet)
(59 BC) Pro Flacco (In Defense of Flaccus)
(57 BC) Post Reditum in Senatu (Speech to the Senate After His Return)
(57 BC) Post Reditum ad Quirites (Speech to the People After His Return)
(57 BC) De Domo Sua (On His House)
(57 BC) De Haruspicum Responsis (On the Response of the Haruspices)
(56 BC) Pro Sestio (In Defense of Sestius)
(56 BC) In Vatinium (Cross-examination of Vatinius)
(56 BC) Pro Caelio (In Defense of Caelius)
(56 BC) De Provinciis Consularibus (On the Consular Provinces)
(56 BC) Pro Balbo (In Defense of Balbus)
(55 BC) In Pisonem (Against Piso)
(54 BC) Pro Rabirio Postumo (In Defense of Rabirius Postumus)
(52 BC) Pro Milone (In Defense of Milo)
(46 BC) Pro Marcello (In Support of the Recall of Marcellus)
(46 BC) Pro Ligario (In Defense of Ligarius)
(45 BC) Pro Deiotaro (In Defense of King Deiotarus)
(44–43 BC) Philippicae (Philippics, against Mark Antony)
(84 BC) De Inventione (About the composition of arguments)
(55 BC) De Oratore ad Quintum fratrem libri tres (On the Orator, three books for his brother Quintus)
(51 BC) De Re Publica (On the Commonwealth)
(?? BC) De Legibus (On the Laws)
(46 BC) Paradoxa Stoicorum (Stoic Paradoxes)
(46 BC) Brutus (Brutus)
(46 BC) Orator (Orator)
(45 BC) Hortensius (an exhortation to philosophy)
(45 BC) Consolatio (on grief and consolation)
(45 BC) Academica (On Academic Skepticism)
(45 BC) De Finibus Bonorum et Malorum (On the Ends of Good and Evil or On Moral Ends, a book on ethics)
(45 BC) Tusculanae Disputationes (Tusculan Disputations)
(45 BC) De Natura Deorum (On the Nature of the Gods)
(44 BC) Topica
(44 BC) De Divinatione (On Divination)
(44 BC) De Fato (On Fate)
(44 BC) De Amicitia (On Friendship)
(44 BC) Cato Maior de Senectute (Cato the Elder on Old Age)
(44 BC) Laelius de Amicitia (Laelius on Friendship)
(44 BC) De Gloria (On Glory)
(44 BC) De Officiis (On Duties)
Cicero's letters to and from various public and private figures are considered some of the most reliable sources of information for the people and events surrounding the fall of the Roman Republic. While 37 books of his letters have survived into modern times, 35 more books were known to antiquity that have since been lost. These included letters to Caesar, to Pompey, to Octavian, and to his son Marcus.Epistulae ad Atticum (Letters to Atticus; 68–43 BC)
Epistulae ad Brutum (Letters to Brutus; 43 BC)
Epistulae ad Familiares (Letters to friends; 62–43 BC)
Epistulae ad Quintum Fratrem (Letters to brother Quintus; 60/59–54 BC)
Ben Jonson dramatised the conspiracy of Catiline in his play Catiline His Conspiracy, featuring Cicero as a character. Cicero also appears as a minor character in William Shakespeare's play Julius Caesar.
Cicero was portrayed on the motion picture screen by British actor Alan Napier in the 1953 film Julius Caesar, based on Shakespeare's play. He has also been played by such noted actors as Michael Hordern (in Cleopatra), and André Morell (in the 1970 Julius Caesar). Most recently, Cicero was portrayed by David Bamber in the HBO series Rome (2005–2007) and appeared in both seasons.
In the historical novel series Masters of Rome, Colleen McCullough presents an unflattering depiction of Cicero's career, showing him struggling with an inferiority complex and vanity, morally flexible and fatally indiscreet, while his rival Julius Caesar is shown in a more approving light. Cicero is portrayed as a hero in the novel A Pillar of Iron by Taylor Caldwell (1965). Robert Harris' novels Imperium, Lustrum (published under the name Conspirata in the United States) and Dictator is the three-part novel series based upon the life of Cicero. In these novels Cicero's character is depicted in a more balanced way than in those of McCullough, with his positive traits equaling or outweighing his weaknesses (while conversely Caesar is depicted as more sinister than in McCullough). Cicero is a major recurring character in the Roma Sub Rosa series of mystery novels by Steven Saylor. He also appears several times as a peripheral character in John Maddox Roberts' SPQR series. The protagonist, Decius Metellus, admires Cicero for his erudition, but is disappointed by his lack of real opposition to Caesar, as well as puzzled by his relentless fawning on the Optimates, who secretly despise Cicero as a parvenu.