I would say that the most important theme of this play is that one's integrity may be worth more even than one's life. In the end, John Proctor must make a choice between these two, and he chooses his integrity. He could confess a lie and avoid hanging or he can keep to the truth and die for it, and he chooses the latter because he knows it is the right thing to do. He very nearly puts his life ahead of his integrity but finds that his conscience will not, ultimately, allow him to do it. Because he is presented as so courageous and sympathetic, we can ascertain that Miller supports this choice.

The setting, during the Salem Witch Trials, is important to the development of this theme because it created a real situation wherein individuals had to make this choice: integrity or life. Many did choose life, and we can certainly understand why, but some did choose integrity, and they died for it.

The most important theme of The Crucible is intolerance. Anyone who doesn't fit in to this rigidly theocratic society is immediately singled out and subjected to ostracism, formal censure, or, as in the case of witchcraft, capital punishment. The hysterical witch-craze that holds Salem in a vice-like grip is used as a means of dealing with those members of society deemed not to be part of the godly elite. The prevailing atmosphere of intolerance is such that there can be no hope of earthly redemption for society's outsiders. If they are to be redeemed, then it will only be by the freely bestowed grace of God. But as far as the civil authorities are concerned, their job is to come down hard on anyone who in any way departs from society's strict norms and values.

Seventeenth-century Salem provides a perfect setting for the development of this theme. Salem is a very small town, which makes it easier for the authorities to control its inhabitants and to display intolerance to those who don't fit society's mold. The town's relatively small size also means that everyone knows everyone else's business, which allows official intolerance to seek out and identify people's faults, foibles, and peccadilloes, the better to correct them by whatever means.

The most important theme of "The Crucible" by Arthur Miller is Persecution. A second important theme is being Judgemental. Concerning the most important theme, Persecution, "The Crucible" deals with the vicious persecution of Elizabeth Proctor, accused of being a witch and practicing witchcraft.

The story is a lesson in how individuals can join with the aggressive masses and turn on those in their own community quite quickly when they perceive someone as being different or acting contrary to their beliefs and value systems. This story deals with religious leaders and the citizens of Salem attacking one of their own. Witchcraft, and its manifestations, have the town fearful, and they seek to punish individuals engaged in this practice. Therefore, they instituted the Salem Witch Trials.

The story is a take on what was happening in America at the time Arthur Miller wrote his story. Hearings to root out Communist sympathizers were taking place in the United States at the behest of Senator Joseph McCarthy and others. Miller used his story of the Salem Witch Trials desiring to root out witches as a way to discuss what was going on in America.

The secondary theme is being Judgemental. This theme deals with people in the town pointing their fingers at others, while not looking at their own behaviors that are vile. It's the classic "when you point a finger at others, you have three pointing back at yourself." This theme deals with getting our own houses (characters) in order before trying to clean up the houses (characters) of others.