Man's Limitations and Potential
The possible range of human accomplishment is at the heart of Doctor Faustus, and many of the other themes are auxiliary to this one. The axis of this theme is the conflict between Greek or Renaissance worldviews, and the Christian worldview that has held sway throughout the medieval period. As Europe emerged from the Middle Ages, contact with previously lost Greek learning had a revelatory effect on man's conception of himself. While the Christian worldview places man below God, and requires obedience to him, the Greek worldview places man at the center of the universe. For the Greeks, man defies the gods at his own peril, but man has nobility that no deity can match.
Doctor Faustus, scholar and lover of beauty, chafes at the bit of human limitation. He seeks to achieve godhood himself, and so he leaves behind the Christian conceptions of human limitation. Though he fancies himself to be a seeker of Greek greatness, we see quickly that he is not up to the task.
Pride and Sin
Within the Christian framework, pride is a lethal motivation because it makes the sinner forget his fallen state. For Christians, men are fallen since birth, because they carry with them the taint of original sin. A man made haughty with pride forgets that he shares Eve's sin, and must therefore be saved by the gift of grace. Only God, through Christ, can dispense this grace, and the man who forgets that fact deprives himself of the path to salvation.
Faustus' first great sin is pride. He does not stop there. Reflecting the Christian view, pride gives rise to all of the other sins, and ends ironically with the proud man's abasement. Faustus moves quickly from pride to all of the other sins, becoming increasingly petty and low.
Flesh and Spirit
The division between flesh and spirit was stronger in Greek thought than in Hebrew thought, but Christians adapted the divide into their own belief system. While Westerners now take this conception of being for granted, the flesh/spirit divide is not a feature of many of the world's major belief systems. Nor is the flesh/spirit divide necessary for belief in the afterlife: both Hindus and Buddhists conceive of the human entity differently, while retaining belief in life after death.
In Christianity, flesh and spirit are divided to value the later and devalue the former. Faustus' problem is that he values his flesh, and the pleasure it can provide him, while failing to look after the state of his soul.
Damnation
Damnation is eternal. Eternal hell is another concept that Westerners take for granted as part of religion, but again this belief's uniqueness needs to be appreciated. While the Jewish view of the afterlife was somewhat vague, Christians developed the idea of judgment after death. Moslems adapted a similar conception of hell and heaven, and to this day eternal hell and eternal heaven remain an important feature of Christianity and Islam. While Buddhists and Hindus have hell in their belief systems, for the most part in neither religion is hell considered eternal. For example, an eternal hell in Mahayana Buddhism would contradict Buddhist beliefs about transience and the saving power of Buddha's compassion.
Not so in Christianity. If Faustus dies without repenting and accepting God, he will be damned forever. As we learn from Mephostophilis, hell is not merely a place, but separation from God's love.
Salvation, Mercy, and Redemption
Hell is eternal, but so is heaven. For a Christian, all that is necessary to be saved from eternal damnation is acceptance of Jesus Christ's grace. Even after signing away his soul to the devil, Faustus has the option of repentance that will save him from hell. But once he has committed himself to his own damnation, Faustus seems unable to change his course. While Christianity seems to accept even a deathbed repentance as acceptable for the attainment of salvation, Marlowe plays with that idea, possibly rejecting it for his own thematic purposes. (See analysis of 5.2-end of the play).
Valuing Knowledge over Wisdom
Faustus has a thirst for knowledge, but he seems unable to acquire wisdom. Faustus' thirst for knowledge is impressive, but it is overshadowed by his complete inability to understand certain truths. Because of this weakness, Faustus cannot use his knowledge to better himself or his world. He ends life with a head full of facts, and vital understanding gained too late to save him.
Talk and Action
Faustus is, with no exceptions, beautiful when he speaks and contemptible when he acts. His opening speeches about the uses to which he'll put his power are exhilarating, but once he gains near-omnipotence he squanders twenty-four years in debauchery and petty tricks. This gap between high talk and low action seems related to the fault of valuing knowledge over wisdom. While Faustus has learned much of the Greek world's learning, he has not really understood what he's been reading. He can talk about potential and plans in terms of a Greek worldview, but he lacks the internal strength to follow through on his purported goals.