"More is a man of an angel's wit and singular learning. I know not his fellow.
For where is the man of that gentleness, lowliness and affability?
And, as time requireth, a man of marvelous mirth and pastimes,
and sometime of as sad gravity. A man for all seasons." - Robert Whittington, 1520
Historians have argued about the accuracy of Bolt's portrayal of More (played in the film and on stage by Paul Scofield), but let's leave that aside for the moment. A Man for All Seasons is a version of history that has something to say about politics, in a general sense. Yes, the specifics are about the English monarchy, but the principles are timeless, I think.
The story centers itself on More's refusal to take an oath declaring King Henry VIII to be the Supreme Head of the Church of England. This is, of course, an action the King takes in order to replace his wife Catherine of Aragon with a new wife, Anne Boleyn. The purpose of this replacement, he reasons, is because Catherine cannot provide him with a son. More has refused to support the marriage, but has said so only to the King. Knowing full well that his words to anyone else could be used against him, he remains silent to all others, even those who hold power over him and threaten to (and eventually do) imprison him.
More is a brilliant man who knows his rights, trusts them, and asserts them. He reasons that his silence is the best means of remaining safe without abandoning his principles and his conscience. He's an exceedingly good man, and a wise one, but he's not at all a politician in the sense that I think we all are familiar with that term. He is fiercely loyal to king and country, but he knows what monsters the court and politics makes of men. More is definitely not a politician, and though that deficiency costs him his life, he leaves that life with the knowledge that he did what was right.
I leave you with one of my favorite moments from the film, in which More tries to talk a young man named Richard (played by John Hurt) out of a life at court.