Shakespeare's treatment of Stoic constancy is essentially traditional. What is more original in the play is his sense of the relationship between constancy and Rome: the paradox that such a heroically individualistic, heaven-aspiring ideal should arise out of a society whose values are public-spirited and earthbound, and the deeper irony that, in fact, an ideal which rests on pretence is thoroughly appropriate to a society governed by appearances and 'opinion'.

In Julius Caesar virtue is defined as Romanness. The characters are obsessively conscious of their national identity: the words 'Rome' and 'Roman' occur seventy-three times, not merely as labels but often with a moral significance.²⁹ Cassius tells the conspirators to 'show yourselves true Romans' (2. 1. 222)—that is, courageous and loyal. Brutus urges Messala, 'as you are a Roman [i.e. honest], tell me true,' and Messala replies, 'Then like a Roman [i.e. bravely] bear the truth I tell' (4. 2. 241-2). To 'be a Roman' in this sense, to live up to the virtues the word implies, is the highest possible praise: Brutus' epitaph for Cassius is 'last of all the Romans' (5. 3. 98). To fail to live up to them, for instance by breaking a promise, is to be no true Roman but guilty of 'bastardy' (2. 1. 135-9). Genuine as the Roman virtues are, there is something faintly absurd in this elevation of a place-name into a moral norm. Its self-referentiality also raises moral problems: if virtue is identified as Roman, and Romanness as virtue, by what standards can Rome itself be judged?

Similar problems are raised by another of the play's keywords, 'honour'. What is 'Roman' and hence praiseworthy is defined by the opinions of other Romans, by honour and reputation. But what is honour? Brutus identifies it with 'the general good':

If it be aught toward the general good,
Set honour in one eye and death i'th' other,
And I will look on both indifferently;
For let the gods so speed me as I love
The name of honour more than I fear death.
CASSUIS. I know that virtue to be in you, Brutus,
As well as I do know your outward favour.
Well, honour is the subject of my story.

(1.2.87-94)

But the honour that is the subject of Cassius' story is (as his image betrays) an 'outward' matter of public recognition; he harps on the contrast between the 'honours that are heaped on Caesar' (135) and the 'dishonourable graves' (139) to which others like himself are relegated. By his deliberate confusion of personal honourableness with public honours, he shows how Brutus' 'honourable metal may be wrought / From that it is disposed' (309-10).³⁰ Later, in the Forum, Antony hammers the word 'honourable' itself into another shape, so that the crowd revile Brutus' honour as villainy. Brutus, who begged them to 'Believe me for mine honour' (3. 2. 14), can have no easy answer, for how can 'honour' be defined except as that which others regard as honourable?³¹

Such questions, as we have seen, were being urgently debated in the late sixteenth century by Neostoics and sceptics like Montaigne. In their terms, the Rome of Julius Caesar may be defined as a society governed by 'opinion'. It erects its own standards into moral absolutes, and is dominated by the fallible and fickle judgements of public opinion. The problematic quality of Julius Caesar, and its preoccupation with questions of truth and judgement, are thus thematically related to its Roman setting. Not that such problems are exclusively Roman; but the Romans are peculiarly prone to them because their pagan and secular world lacks absolute values. Relying purely on human reason, they fail to recognize how far they are in fact guided by opinion; as Montaigne remarked in the 'Apologie', the two can be hard to distinguish in their 'inconstant vanitie and vaine inconstancy'.

The 'public temper of Rome' (in Eliot's phrase) means that truth is constituted by judgements arrived at through a process of public observation, discussion, and persuasion. Characters continually observe and attempt to 'construe' one another's behaviour and character, as Cassius observes and construes Brutus (1.2. 34, 47), Caesar and Antony observe Cassius, and everyone observes Caesar.³² They also continually attempt to persuade one another. The Rome of Julius Caesar echoes with rhetoric; not only in the great public scenes but in private encounters and even in soliloquy, characters use language to persuade others (or themselves) to a desired opinion.³³

In such a society there is a constant temptation to confuse what seems true (or can be made to seem true) with what is true. 'Fashion it thus' (2. 1. 30), Brutus tells himself, construing Caesar's actions after his own fashion. The conspirators want Brutus in their plot because, as Casca puts it,

he sits high in all the people's hearts,
And that which would appear offence in us
His countenance, like richest alchemy,
Will change to virtue and to worthiness.

(1.3. 157-60)

Metellus similarly argues that Cicero's 'silver hairs will purchase us a good opinion' (2. 1. 143-4). Their assumption that what matters is how the conspiracy is seen by others is unconsciously echoed by Brutus a little later, when he urges the conspirators to kill Caesar without anger:

This shall make
Our purpose necessary, and not envious;
Which so appearing to the common eyes,
We shall be called purgers, not murderers.

(177-80)

Of course, the fact that the murder appears necessary does not make it so—any more than the fact that the murderers 'seem to chide' their rage means that they are in fact passionless.³⁴ Brutus has temporarily lost sight of the distinction he later passionately regrets: 'That every like is not the same, O Caesar, / The heart of Brutus ernes to think upon' (2. 2. 128-9). The Romans of Julius Caesar are fatally prone to overlook the difference between 'like' and 'the same'.

The most critical way in which opinion displaces knowledge in the play is the failure of self-knowledge. Shakespeare's Romans are more concerned with the way in which others perceive them than with their own self-awareness—a flaw which, I have suggested, is inherent in both Senecan and Ciceronian Stoicism. The issue is most clearly defined in a passage of Socratic dialogue between Brutus and Cassius:

CASSIUS. . . . Tell me, good Brutus, can you see your face?
BRUTUS. No, Cassius, for the eye sees not itself
But by reflection, by some other things.
CASSIUS. 'Tis just;
And it is very much lamented, Brutus,
That you have no such mirrors as will turn
Your hidden worthiness into your eye,
That you might see your shadow. I have heard
Where many of the best respect in Rome—
Except immortal Caesar—speaking of Brutus,
And groaning underneath this age's yoke,
Have wished that noble Brutus had his eyes.

(1.2. 53-64)

Cassius proposes, and Brutus accepts, that it is impossible to see yourself except as reflected in the eyes of others. Self-knowledge can be gained only through the opinions held of you by others, whose opinions in turn are validated by the 'respect' in which they are held . . . The sense of endless regression is underlined by Cassius' imagery, which echoes the discussions of honour by Cicero (in Tusculans 3) and later writers such as Du Vair. For Cicero, true honour is the accurate reflection of virtue, but false honour, popular reputation, is a mere shadow. Cassius' word 'shadow', which hovers between the two meanings, suggests that the distinction is itself a somewhat shadowy one.³⁵

Brutus, in a flash of insight, objects

Into what dangers would you lead me, Cassius,
That you would have me seek into myself
For that which is not in me?

(65-7)

Cassius brushes aside the question; his task is to induce Brutus to abandon his own sense of his 'self, and accept instead the image of Brutus the tyrannicide reflected in Cassius' glass. In the orchard scene we see this process completed, as Brutus is drawn to accept 'the great opinion / That Rome holds of his name' (1. 2. 318-19), as embodied in the cryptic and forged letter which he has to 'piece . . . out' by the light of 'exhalations whizzing in the air' (2. 1.51, 44). It is a wonderfully suggestive image of the corruption of self-knowledge by 'opinion'. From now on Brutus will, as Cassius wishes, have and be governed by 'that opinion of [him]self / Which every noble Roman bears of [him]' (92-3).

This failure in self-knowledge of the play's most introspective character is symptomatic of a world in which people see their actions most clearly as reflected in the eyes of others. It is not surprising that one of the recurring images is that of the theatre, where characters' performances are judged by an audience: Casca sees Caesar's refusal of the crown as a performance clapped and hissed by the people (1.2. 258-61), and Cassius and Brutus, standing over Caesar's body, speculate how future audiences will respond when the 'lofty scene' is 'acted over' (3. 1. 112-19). The most striking of these images, Brutus' charge to the conspirators to emulate the 'formal constancy' of 'Roman actors', suggests how constancy in this world becomes defined as a form of performance. But the link between constancy and Roman acting, of course, had already been made by Cicero.