Consider an angle that incorporates the background of the play itself (1692) and the political background at the time Miller wrote The Crucible (1953). In this case, an introduction would include a comparison of these two backgrounds. The play is set in 1692 and is loosely based on a real episode in Salem, Massachusetts when many people were accused of witchcraft and twenty people were put to death. The hysteria that fueled these accusations comes from the strident religious leaders and the oppressive religious culture of the people during that time. Compounding this, Miller presents some corrupt leaders (namely Parris and Danforth) who would rather uphold their own authority rather than challenge the accusers and thereby challenge their religion and traditions.
In the early 1950s, a similar hysteria was occurring in America and it was called McCarthyism. This was a "witch hunt" led by Senator Joseph McCarthy. The witch hunt, as it was called then, sought to rid America of Communist influences. Thousands of Americans were arrested, some imprisoned, and some executed. Comparing the 1692 trials and the McCarthy hearings of the 1950s, both authoritative institutions condemned the so called witches and so called Communist sympathizers as threatening the country's way of life. Both authorities believed so much in their way of life, that it was the best in the world, that they persecuted anyone whom they thought might stray from their biased vision. In the overture at the beginning of Act One, Miller (narrator) notes this and alludes to a historical trend:
They believed, in short, that they held in their steady hands the candle that would light the world. We have inherited this belief and it has helped and hurt us.
A thesis statement, even one that focuses more on the play than the McCarthy angle, would address the issue that an ideologically oppressive government (local or federal) that threatens to suppress or imprison individuals who do not conform to their beliefs is not only inhibiting freedom; they are encouraging, or at least daring, the very rebellion they are trying to suppress.