The redeemed Ebenezer Scrooge is a wonderful human being.

At the start of “A Christmas Carol,” Charles Dickens describes his famous character as a “squeezing, wrenching, grasping, scraping, clutching, covetous old sinner,” someone from whom “no steel had ever struck out generous fire” and whose coldness of heart is reflected in his frozen facial features, his barely heated office, and his wintry personality. Devoid of human warmth, we are told, Scrooge “carried his own low temperature always about with him.”

Yet by the end of the book, Scrooge has become “as good a friend, as good a master, and as good a man, as the good old city knew, or any other good old city, town, or borough, in the good old world.” Gone is the caustic misanthrope who used to react to Christmas with a sneering “Bah, humbug!” In his place is a man of whom “it was always said … that he knew how to keep Christmas well, if any man alive possessed the knowledge.” Walking about the streets on Christmas Day, Scrooge smiles delightedly at everyone, and when passersby wish him a merry Christmas, he reflects that “of all the blithe sounds he had ever heard, those were the blithest in his ears.”

Scrooge’s transformation is one of the most striking and uplifting in all of Anglo-American literature. It is strange that when we use the term “Scrooge” today, we don’t refer to a person who has undergone a radical self-improvement but to someone who resembles the antisocial hoarder of the book’s opening pages. What makes it all the stranger is that, in Dickens’s beloved fable, the spiteful early Scrooge doesn’t last beyond those first pages.

Almost as soon as his series of ghostly visits begin, Scrooge starts to change. For example, when the Ghost of Christmas Past shows Scrooge his own much younger self, alone and abandoned on Christmas Day, he regrets his heartlessness of the night before, when he chased away a hungry child who had hoped to trade a song for a coin. “It’s too late now,” he mutters to himself. When the ghost asks what he means, Scrooge explains: “There was a boy singing a Christmas Carol at my door last night. I should like to have given him something.”

Thereafter, Scrooge grows steadily more penitent and determined to turn over a new leaf. As the Ghost of Christmas Present shows Scrooge the brightness and warmth with which Christmas is celebrated in many homes, writes Dickens, “he softened more and more,” and wished that “years ago, he might have cultivated the kindnesses of life for his own happiness with his own hands.” By the time he meets the ominous and unspeaking Ghost of Christmas Yet to Come, Scrooge accepts whatever lies in store as necessary for his own moral self-improvement.

“I fear you more than any specter I have seen,” Scrooge tells the ghost. “But as I know your purpose is to do me good, and as I hope to live to be another man from what I was, I am prepared to bear you company, and do it with a thankful heart.”

All of which suggests that the Scrooge we meet in the book’s first chapter is not really a bad man, but an unhappy one. He isn’t incorrigible; he is depressed. Lacking joy in his own life, he sees no reason to increase the joyfulness of anyone else’s. And if Scrooge harbors a particular resentment for Christmas, there is a reason for that: Some of the most painful events of his life occurred on Christmas.

As a child, he is abandoned on the holiday, forced to remain at school alone while his classmates go home to family. As a young man trying to build a career, he is crushed when his fiancée breaks off their engagement at Christmastime, claiming he cares more about business than about her. By the time he is an older adult, his whole life revolves around the successful business he has built with his partner and only friend, Jacob Marley. But on Christmas Eve, exactly seven years before the story begins, Marley dies. Is it any wonder that Scrooge is so embittered at the holiday’s return each year?

Dickens opens “A Christmas Carol” with an unsparing portrayal of Scrooge’s ill temper, stinginess, and lack of charity. But there is no indication that Scrooge is crooked or deceitful, that he doesn’t settle his bills promptly, that he cheats on his taxes, or that he falls short of anything the law requires of him. We are given no reason to believe he has ever defrauded his investors, betrayed any confidences, bribed public officials, or manipulated others to unfair advantage. He scrupulously pays what he owes and just as scrupulously collects what is owed to him. There is no mention in the text of Scrooge’s satisfied customers, but there must have been many of them for him to have grown so rich. He may not be charming and hospitable, but he is no swindler.

To be sure, Scrooge is implacably uncharitable. In that he resembles a great number of people. Like countless others even in our own time, Scrooge at the start of the book feels no inclination to help anyone else and angrily refuses when asked to reach into his pocket to aid the poor. His attitude — that he pays his taxes, which in turn pay for the workhouses in which the needy are employed — is similar to views expressed today by individuals, some quite prominent, who regard it as primarily the role of government to help the needy.

But Scrooge, the most intelligent character in Dickens’s fable, shows himself to be a quick study and capable of change. A consummate man of business, he learns — with the help of the three Christmas ghosts and the phantom of his old friend Marley — that ultimately the most rewarding investments are the ones made to improve the lot of the less fortunate.

“A Christmas Carol” is the parable of a man long trapped in an emotional ice block who discovers that the key to his freedom is to reach out and benefit others for no other motive than to benefit them. After living so long without happiness, Scrooge learns that the deepest happiness comes not from what others do for him, but from what he is prepared to do for others. That is a lesson none of us can ever learn too well, on Christmas Day and every other day.