Martyrdom
One of the most explicit philosophies Eliot explores is what constitutes a true Christian martyr. As Thomas explains in his Interlude sermon, a martyr is not merely one who dies for God, but rather one who allows himself to be "the instrument of God" (199). He argues that a martyr is not made by accident, but rather by God's will. Thomas's journey in Part I is marked by his acceptance that he wants to seek martyrdom for the sake of his pride and worldly glory, and his subsequent willingness to rid himself of those desires and to die solely for God's cause. Further, the play explores martyrdom in terms of how it impacts the true believers who come afterward. The chorus must come to terms with the fact that a martyr's death saddles them with a burden to validate the sacrifice through their own lives. In many ways, a true martyr must die as Christ did – because God wills it – and those Christians who follow are expected to subsume their own lives in service of God for that reason.
Time
The question of time runs throughout the entire play and informs the theology behind Thomas's recognition of his role as a martyr. Time is presented as an earthly, human concern in the play. Time leads humans to think of events in terms of cause and effect, and to therefore make decisions on the basis of efficiency and outcome. However, to consider anything from this perspective allows a person to justify his actions, so that the distinction between good and evil is blurred. Thomas considers that his decision – to willingly submit himself to be an instrument of God's will – is a decision made outside of time. It is not made for its effect, and in fact cannot be understood by any human, since no human can understand God. Thomas suggests that from God's perspective, the limitations of time do not apply. The play proposes that humans are tormented by the difficulties and complications that time puts upon us, whereas ridding ourselves of our personalities in order to be God's instruments allows us to transcend those limitations.
"The wheel"
"The wheel" was a common image in medieval theology and helps us to understand the ideas at work in [Murder in the Cathedral]. Associated primarily with the medieval thinker Boethius, the wheel image posits that God sits at the center of a large wheel, and hence understands the system behind its rotations. Humans, who live at various places along the edge of the wheel, are confounded by those rotations and cannot glimpse the order behind them. Thus, serenity comes in accepting that we can never understand the workings of the universe and should instead endeavor to transcend our humanity so as to deserve God's protection after death.
Thomas enters the play prepared to seek martyrdom for earthly reasons, but learns that he must simply submit himself to God's control. In effect, he has to rid himself of his earthly ambitions because they are necessarily flawed. Those ambitions cannot possibly take the universe into account. One of the lessons Thomas learns – and which he teaches the Chorus through his example – is that our lives of suffering and difficulty are illusions that we overvalue. We can never understand them, and so we should not dwell on them. Instead, we should focus on pleasing God, in faith that he knows why and how the wheel turns, and will reward us for our faith in a way we could never reward ourselves because of our limited perspectives.
Politics
Eliot aimed to craft a play built around ritual rather than around human psychology, and yet the story of Thomas Becket is too heavily political to support a solely theological framework. Politics are present throughout the play, from the exposition given by the priests before Becket arrives to the arguments the knights make to Thomas and directly to the audience. To some extent, these political elements are there to round out the story, to give an informed audience its expected details. However, the political arguments also represent the aspect of Thomas's personality that he must overcome in order to be worthy of true martyrdom. By acknowledging Thomas's political nature and past, Eliot endows him with a palpable quality that the audience will see him overcome. He wishes to be God's instrument, and so refuses to concern himself with political questions. Interestingly, Thomas cannot help himself from engaging in some political banter with the knights in Part II, which suggests that no person can ever fully rid himself of his personality; he can only endeavor to do so up to the limits of his humanity.
In terms of the chorus, the complicated politics stand in stark contrast to the reality of their everyday lives. They are interested in political issues only insofar as they complicate the suffering of their daily toil. By emphasizing the chorus so strongly in the midst of such a political story, Eliot implicitly suggests that the nuances of politics are less valuable and spiritual than the community of Christians who attempt to please God through their simple, everyday lives.
Suffering
"Suffering" in the play has two meanings. In its most common usage, suffering means "to undergo pain or distress." The horrific imagery of the chorus's speeches, as well as the detail they give about their daily toil, stresses how much suffering they undergo. Because of this suffering, they wish mostly be left alone. Eliot's ultimate message, of course, is that for true spiritual fulfillment, we must not simply retreat into our earthly suffering, but rather overcome it and devote ourselves to serving as God's instruments. However, the extent to which he presents extreme suffering as a fact of life certainly informs the play's messages.
"Suffering" is also manifest through the dichotomy Thomas presents between "action" and "suffering." In this context, suffering is best defined in terms of patience and waiting. From this definition, the theme is less about overcoming physical distress and more about remaining patient in the face of worldly events that we cannot understand. Thomas suggests that some people act to change their fates, while some simply wait to see what happens. His perfect middle road is an active patience, an active choice to be submissive before God's will.
Opposites
In a variety of ways, Eliot explores the theme of opposites: elements that contain a contradiction within them. The most explicit manifestation of the theme is the mystery of Christ's death, which is paralleled in the death of martyrs. As Thomas explains in his Interlude sermon, Christians both celebrate and mourn these deaths. They mourn the wicked world that makes those deaths necessary, while celebrating the bravery and glory of the individuals who make the sacrifice. Likewise, there is a contradiction in what the chorus is encouraged to accept in the play. They are promised a greater, more fulfilling existence if they accept their burden in validating the sacrifices of martyrs, but this burden also makes their lives more difficult. They cannot simply retire into their suffering, but must more directly confront the limitations and difficulties of the physical world. Finally, Eliot explores opposites through the chorus's speeches, especially in Part II, in which they continually posit elements that are both positive and negative at once.
Responsibility
There are two emotional journeys in the play: that of Thomas and that of the chorus. Both of these journeys entail accepting responsibility for spiritual transcendence. Thomas must accept that his responsibility is greater than that which he owes to himself. He enters the play prepared for martyrdom, but for the wrong reason: to bolster his own pride and reputation. His journey in Part I entails his realization that he must die as God's instrument, so as not to waste the death. His responsibility to his church means he must rid himself of personality and be submissive to God.
However, the chorus has a much more complex obligation. As they note many times, they are powerless to impact their world. Instead, they merely hope for minimal interference into their already-difficult lives of toil and struggle. What they prefer at the beginning of the play is an existence of "living and partly living," a miserable but predictable life in which they are not forced to take responsibility for anything other than their immediate survival. They even hope Thomas will not return, since that will potentially make their lives more difficult by forcing them to become more involved. They prefer to be complacent. Thomas poses a situation where they have a share of the "eternal burden," where a martyrdom is meaningless without an audience or congregation to sanctify it and validate it through their lives. The chorus is frightened of the potential for being engaged and responsible, since a life of passion requires them to more directly confront the iniquity of the world. Their journey in the play is learning that their spiritual fulfillment will be greater even if their physical challenges intensify, and so they accept their responsibility and ask God and Thomas to help them.
