The common man is effectively the audience(if you think that the majority of people watching the play would be a base and crafty figure who dons different costumes to enact the roles of More's steward, boatman, jailer, foreman of the jury, and executioner (called "headsman"). Everyday jobs and people rathan than Sir Thomas Moore, etc..) The Common Man changes outward identities as easily as he changes hats, but his essential, opportunist self remains the same. He serves as a foil to More's integrity and reinforces the heroism of More's martyrdom. By alienating the common man, Brecht therefore alienates the audience, and gets across his point that individualism and spirituality is key. The things that More is passionate about, the spiritual rather than the body, individualism in a time of greed, that is what the audience is supposed to remember, reverently.
The brecht alienation technique makes the audience feel involved in the play. Unlike traditional plays where the audience watches the play take place on a stage, Bolt use of the common man reminds the audience that they are really one in the same and that the common man is the audience.
i cant remember the quotes but something along the lines of "the sixteenth century is the year of the common man, just like all other years" and "if you see me around, recognise me"
hope that sorta helps although im like 2 years 2 late XD