The conflict between the patricians, or traditional ruling class, and the plebeians, or common people, is central to the play. At the opening of the play, the plebeians are rebelling against the patricians, whom they accuse of hoarding grain while the plebeians starve. The tribunes Brutus and Sicinius are of the plebeian class and representatives of that class. Their mistrust and dislike of Coriolanus is partly their class's mistrust and dislike of the patrician class. In addition, Coriolanus fosters this mistrust and dislike because of the pride and contempt he displays towards the plebeians.
The patricians, equally, mistrust and scorn the plebeians. Both Menenius and Coriolanus dismiss them as fragments, incomplete people: words applied to them include "great toe?(I.i.142), "cobbled [patched] shoes?(I.i.182), and "shreds?(I.i.194). They are "dissentious rogues?(I.i.150). Menenius and Coriolanus, being patricians, are biased witnesses, but their judgments are validated by the action of the play, which is not neutral with regard to class. Shakespeare assumes that class is a predictor of intelligence, rationality, and ability to govern. The plebeians cannot be relied upon to think for themselves or stick to a decision once they have made it; they are easily manipulated by the self-serving tribunes; they are cowardly in battle; and they are unable to take any responsible role in government. Coriolanus is driven out of Rome because Brutus and Sicinius play upon the plebeians?fears that he will become a tyrant if elected consul. Repeatedly, the patricians are the voice of reason; they do not want Coriolanus to be banished; they try to give him a fair hearing when he is being condemned by the plebeians; and at the end of the play, their Volscian equivalent, the Lords, again try to give Coriolanus a fair hearing before he is hacked to death by the Conspirators.
Pride is Coriolanus's main problematical quality, and it defines his fate. His pride partly arises from his remarkable martial qualities, but it prevents him making the necessary compromises to become a political leader. If he were not so proud, he would be viewed by the plebeians both as a war hero and a suitable consul. They would see him as they do Menenius, as "one that hath always loved the people?(I.i.41?2), rather than as "chief enemy to the people?(I.i.5?) and "a very dog to the commonalty?(I.i.23). Coriolanus's pride leads to his offending the plebeians at every step, and prevents him from making amends to them. He even responds to his banishment with pride, insisting that it is he who banishes the Roman people, and hurling insults at them. This makes his future rehabilitation in their eyes all the more unlikely, and means that Coriolanus is permanently trapped in his stubborn resolve to reject his native land. Similarly, his pride is a factor in antagonizing Aufidius, with whom Coriolanus takes refuge in exile ("He bears himself more proudlier, / Even to my person, that I thought he would / When first I did embrace him.??IV.vii.8?0).
Different kinds of virtue
"Virtus,?valiantness or martial valor, was the most highly prized character virtue in ancient Rome at the time the play is set. It encompassed courage, boldness, heroism, and resoluteness. Coriolanus has these qualities in abundance, but it is at the expense of another more humble virtue, "pietas,?or love and respect for family, country, and gods. While "virtus?was unquestionably of more value in war time, "pietas?was vital in peace time to provide the ability to compromise and forgive that held society together.
The two virtues often find themselves in conflict in the play, and Coriolanus, by upholding "virtus?and neglecting "pietas,?cuts himself off from society and humanity in general. While the plebeians are grateful for Coriolanus's war record, they do not value "virtus?as highly as he does. Understandably, they are more concerned with the quality of their daily lives and being listened to and treated with respect. Coriolanus cannot provide these elements ?in fact, he seems to work against them. He is too inflexible in his warrior-like stance to make the compromises necessary to making society function smoothly. In banishing him, the plebeians deliver their verdict on "virtus,?though naturally they regret their rashness when another attack on Rome is imminent. Finally, Coriolanus, under the influence of Volumnia, does set aside "virtus?and bows to the demands of "pietas?in his abandonment of the attack on Rome.
The two virtues, however, have not been reconciled; they cannot coexist in Coriolanus. It is Coriolanus's tragedy that this allowance of humanity into his nature is fatal to him; he is aware that it will lead to his death. Aufidius, another inflexible man wedded to "virtus,?is unable to forgive Coriolanus for his betrayal of "virtus.?Aufidius is also unable to overcome his own warlike rivalry towards Coriolanus ?another aspect of "virtus??and so has him killed.
The play does not reconcile the two virtues but rather, shows ways in which they conflict. It also shows their importance changing with changing times: "virtus?is necessary for defending Rome and expanding its influence through conquest, but "pietas?is necessary for building a cohesive society. With the death of Coriolanus and the ascendancy of politicians like Menenius, Brutus, and Sicinius, the suggestion is that "virtus?has had its day and "pietas?is the more timely quality.
The past versus progress
The struggle between the patricians and the plebeians is also a struggle between the past and progress. The patricians support the ways of the past, including the traditional hierarchical system of government, whereas the people want change, including a share in government. This theme is embodied in Coriolanus himself, who is a war hero of the traditional kind at a time that has moved beyond the values he represents. Now, political skill, not immovable courage, is what is needed for Rome to progress.
An atmosphere of uncertainty pervades this play due to shifting allegiances. It is difficult to identify who is a friend and who is an enemy. On the one hand, Coriolanus is a war hero who has a claim on the people's loyalty for his military services. On the other hand, the people dislike his pride and under the influence of the tribunes, quickly become his enemy and drive him out of Rome. This turns Coriolanus's allegiance from Rome to his former enemies, the Volscians. Aufidius and Coriolanus are sworn enemies who become friends after Coriolanus is banished, but envy and rivalry gain ascendancy in Aufidius's mind and he once again becomes Coriolanus's treacherous enemy.
While such shifts come naturally to Aufidius and he is skilled at hiding them when needed, Coriolanus is of an open and guileless nature, so that everyone knows whose side he is on. As the age of martial conquest begins to give way to an age of political manoeuvring, it is no accident that Aufidius and the other politicians, Menenius, Brutus and Sicinius, survive, but Coriolanus dies.
The play's treatment of the battles also shows how times are changing. The audience sees little actual fighting but hears a large amount of military intelligence, including an entire scene (IV.iii) featuring a Roman spying for the Volscians ?another example of changed allegiance. The days of heroic action, when allegiances were clear, are past, and have given way to the compromises, subterfuge, negotiations, alliances of convenience, and other 'grey areas?of the political arena.