I didn’t intend to write on Andrew Roberts’s biography of Winston Churchill, because so many smart people have written on it so well. Also, I don’t belong to the Churchill cult. He was a great man, arguably the greatest of the 20th century, and right on the central question of his age, the meaning of Hitler. He had both political and literary genius, the first Western political figure of whom that could be said since Lincoln. He was brave and he was a visionary; he understood and wrote about the implications of splitting the atom long before it was split. He was also a person of titanic self-regard driven by a sense of destiny that occasionally verged on the half-mad. He made blunders for which others suffered and forgave himself too quickly and too much. And he was bloody-minded. “I love this war,” he confided to a friend at the height of World War I, when he was first lord of the admiralty. “I know it’s smashing and shattering the lives of thousands every moment — and yet — I can’t help it — I enjoy every second of it.”

He did. War was opportunity. He didn’t think the lights were going out all over Europe, he thought the lights were about to shine brightly on his name.

And yet. What a warm and splendid book Mr. Roberts’s biography is. It is intelligent and fluid; he doesn’t lard things up to show you the depth of his research, but tells you what is important, with verve and sympathy. As you read you trust his judgment.

It reminds me what a moving life Churchill’s was, and what a struggle. His father, who treated him as an afterthought, did not live long enough to admire him; his mother became fully invested in him only once she understood he was a winner and would reflect well on her. His response to their neglect was a love that looks very much like gallantry.

Mr. Roberts gives fresh attention to the meaning and origin of Churchill’s domestic policies, which were central to his political life and usually get short shrift.

This feels pertinent now. Some readers will have found themselves the past few years, even before Donald Trump, certainly since the wars and the crash of 2008, revisiting and questioning political stances and assumptions they’d previously held with confidence. That questioning has been playing out in this space since 2005. For some Republicans, the question has been whether to change the party or leave it. For some Democrats, it’s “Am I completely comfortable in a party that appears to be charging, culturally and economically, to the hard left?”

Churchill, elected to Parliament as a Tory and from an ancestral Tory family, crossed the aisle early in his career and joined the Liberals. He later rejoined the Conservatives. Mostly this was due to his sense of what was required at that moment in terms of policy. He had a shrewd sense of the lay of the land; for all his intellectual flights he believed in realism. Like a true aristocrat, Mr. Roberts notes, he was not a snob; he had a filial respect for and sense of responsibility toward “the masses.”

The proximate reason for his bolting the Tories was high tariffs; he was a free trader. But more was at play. His early political career was marked by a gradual coming to terms with the England he was seeing all around him and its ossified politics and parties. He had believed, in Mr. Roberts’s words, “that social reform was not the exclusive preserve of the Liberals but could be appropriated by what he called ‘the Tory democracy.’ ”

But they weren’t good at appropriating. Churchill came out for the progressive income tax, with total exemptions for the poor. He backed the “minimum standards of life and labour,” policies that came to be the basis of the modern welfare state.

But free markets and competition mattered to him. Social spending was desirable — "spread a net over the abyss" — but it depended on “the existing competitive organization of society.” We need private enterprises, he said, “and do not grudge them their profits.” He opposed socialism. Were the early Christians socialist in spirit and practice? “The Socialism of the Christian era was based on the idea of ‘All mine is yours,’ ” he said. The socialism of the Labour Party “is based on the idea that ‘All yours is mine.’ ”

When he turned on the Tories it was wonderful work. They and the “protectionist manufacturers” say they support tariffs “because they love the working man,” he said in a speech in Manchester. “They love the working man, and they love to see him work.”

He was vivid, not vague, about his changes of mind. He told voters, “I admit I have changed my party. I don’t deny it. I am proud of it.” He didn’t think the Tories were an especially moral lot, and he didn’t think they saw the nation or its needs clearly. “I am delighted that circumstances have enabled me to break with them while I am still young and still have the first energies of my life to give to the popular cause.” He told his constituents he had plenty of loyalty — not to a party, but to them.

Years later, when he popped back to the Tories — he had a way of joining each party just before it began its ascent — he acknowledged what people were saying behind his back, and defused it with laughter. “Anyone can rat,” he said, “but it takes a certain ingenuity to re-rat.”

He was candid in other ways. He rudely opposed women’s suffrage and said only “undesirable classes” of women wanted the vote. Suffragettes were rude right back, hounding him at his rallies and ringing bells to drown out his voice. He admitted he found it difficult to change his mind. “I was steadily moving forward to the position of whole-hearted supporter” of women’s rights, but he had been “much put off” by their efforts to curtail his speech and didn’t want to be seen “giving way” to such tactics.

It is good when politicians are frank about their opponents’ methods, and reasonable to admit you don’t want to appear to be bowing to them. Nobody likes to be bullied.

Something especially pertinent to this moment: Churchill was a warrior who threw insults like lightning bolts. He fought hard for his side. But he said political division “does not in my mind prejudice personal relations.” He was broad in his friendships, which encompassed figures of left, right and center. Mr. Roberts notes he was “privately affable” with friends and foes. He dined with the Fabian socialist Beatrice Webb. He separated politics from personal friendship, in part, Mr. Roberts implies, because he understood we are not only political beings. His openness was misunderstood by people “who assumed he was being insincere either in the friendship or in the politics. In fact he was being neither.” If he liked you or valued your mind, you were in.

This old style should be made new again.

And Merry Christmas. May you reconsider whether someone is really a foe, and if he is, dine with him anyway.

Reprinted by permission from peggynoonan.com.