Final answer:
In the opening scene of 'Julius Caesar,' the commoners display festivity, rebellion against elites, and fickle behavior, highlighting the play's themes of class tension and the volatility of public opinion.
Step-by-step explanation:
The opening scene of Julius Caesar presents the commoners or "commons" of Rome who exhibit a range of attitudes and behaviors. These characteristics include festivity and a sense of rebellion against the ruling elites, as they are celebrating Caesar's recent victory despite the disapproval of the patricians. They are also depicted as fickle and easily swayed, a point the tribunes Marullus and Flavius criticize when they chastise the commoners for their lack of loyalty to Pompey, whom Caesar has just defeated.
These attributes of the commons are reflective of the broader themes in the play, such as the tension between the elite and the lower classes, and the volatile nature of public opinion and mob mentality. Shakespeare illustrates early on how public opinion can be a powerful but unstable force within Roman society.