Examine the play as a conflict between king Henry's desires and More's principles.
Robert Bolt's A Man for All Seasons is essentially the dramatisation of a conflict between the will of a king and the conscience of a man. King Henry VIII's personal desires collide with the moral and religious principles of Sir Thomas More, and the tragedy grows out of More's refusal to surrender his integrity to royal power.
Henry's desires. The King is determined to divorce his wife, Catherine of Aragon, who has borne him no male heir, in order to marry Anne Boleyn. When the Pope refuses to grant an annulment, Henry breaks with Rome and has himself declared Supreme Head of the Church of England. His desires are for a new marriage, a legitimate son, and absolute acknowledgement of his authority. He craves not merely obedience but approval, and above all the approval of the one man whose goodness he respects, Thomas More.
More's principles. More, a devout Catholic and Lord Chancellor, cannot in conscience accept the King's divorce or his claim to headship of the Church, which he believes belongs to the Pope. Yet he does not openly rebel. He resigns his office, withdraws from public life and takes refuge in silence, refusing to swear the Oath of Supremacy while giving no reason. His principle is that a man must not act against his own conscience, for "when a man takes an oath, he is holding his own self in his own hands like water".
The nature of the conflict. The clash is therefore between raw political power and private conscience, between what the state demands and what the individual believes to be right. Henry and his agents, chiefly Thomas Cromwell, cannot tolerate More's silence, for his very refusal to endorse the King is a loud reproach. Power seeks not only compliance but the surrender of the soul, and this More will not give.
The pressure and the outcome. More is pressed on every side: by Cromwell's cunning, by the threats of the Duke of Norfolk, by the pleas of his own family, and finally by the perjury of the ambitious Richard Rich, whose false testimony secures More's conviction. Sentenced to death, More at last breaks his silence to affirm his faith, and he goes to the scaffold rather than betray his conscience.
Significance. The conflict makes the play a study of integrity under tyranny. Against the compromisers, Rich, Cromwell, even the pragmatic Norfolk and Wolsey, More stands as the man who will not bend, "a man for all seasons", whose selfhood is inseparable from his conscience. His death is a defeat in worldly terms but a triumph of principle.
In conclusion, the play is indeed a conflict between King Henry's desires and More's principles: the King's craving for divorce, an heir and total supremacy meets the immovable conscience of a man who chooses death over self-betrayal, and in that collision Bolt affirms the supreme value of personal integrity.