English Renaissance Man
About fifteen years before More's death, his friend Robert Whittington paid tribute to him, writing,
"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."
So, this Whittington guy was definitely a major More cheerleader—as was Robert Bolt, who wrote the script. And Bolt makes sure that we don't think of More as a stick-in-the-mud. When we see More at the beginning, joking around with friends and family, we understand that he's more than capable of normal human emotions. He's not always super serious, and he's more mentally balanced than his opponents.
The idea that More is "a man for all seasons" is even teased out in the movie's imagery a bit. We see that it's a beautiful day at the beginning of the film—either spring or summer. But as More's fortunes shift, we see it become winter as he languishes in the Tower of London, imprisoned for treason and at risk of a death sentence.
But then, by the time he's about to put his head on the executioner's block, it's beautiful outside again. Throughout all these changes, More himself hasn't really changed that much. No matter what time of year it is or how the political winds of fortune shift, he remains true to himself. He doesn't just roll with the whims of kings like his friend Norfolk or his enemy Cromwell do. He remains faithful to the end.