What a contrast. While the diplomats and heads of state were quarreling at the United Nations, we dropped in on the 100th anniversary of Forbes Magazine. There, at Pier Sixty on the Hudson River, hundreds of readers, advertisers, and writers showed up for a buffet dinner with the magazine’s chairman and editor-in-chief, Steve Forbes, and a galaxy of capitalist and cultural heroes.

It turned out to be a diverse crowd. Black, white, right, left, American, foreign. Oilman Boone Pickens, rapper and entrepreneur Sean “Diddy” Combs, and financial titan Sandy Weil were there. So were, to name but a few, the Bangladeshi entrepreneur Muhammad Yunus (a Nobel laureate), and artist Jeff Koons. Warren Buffett got on stage with Stevie Wonder and sang a duet of “The Glory of Love.”

Across town that morning, delegates to the United Nations had sat gritting their teeth while President Trump gave his speech (a humdinger, in our opinion). Then the striped pants set left to give their interviews complaining about him. Maybe the U.N. should invite Steve Forbes to speak. He could talk about the logic, the spirit, and the optimism of capitalism and what it has done this past century (in addition to paying the U.N.’s bills).

At Pier Sixty, Steve Forbes talked about how his grandfather, B.C., had started Forbes in the same year as the Bolshevik Revolution. Fresh off the boat from Scotland, B.C. had been so eager to demonstrate his journalistic esprit that he told one editor he’d work for a week without pay. He got the job. Then, under a “nom de plume,” B.C. got a second business reporting job at a another paper. Supposedly the competing editors started boasting about their reporters, without realizing they were both B.C. Forbes.

B.C.’s son, Malcolm, eventually became captain of Forbes and introduced, among other things, the Forbes 400. That’s the list of the richest people in America. In an editorial in the 100th anniversary issue (Warren Buffett is on the cover), Steve Forbes relates that when his father first suggested such a list, his editors warned that it wasn’t feasible. They feared it would inspire thieves and kidnappers.

Malcolm Forbes plunged ahead. He invested enormous amounts of reporting in the list each year. It soon became an American institution, inspiring millions. For it turns out that Americans don’t resent successful businessmen and women. They admire them. They, too, want to be rich. A failure to appreciate this, in our opinion, is one of the blunders that caused Hillary Clinton to underestimate Donald Trump.

The Democrats just couldn’t see that one reason such huge crowds thronged to airport hangars to see Mr. Trump pull up in his gilded jetliner is that millions admire his success. They want to be like him. The Forbes 400 shows some of them can. The list has many regulars. But each year it drops some names and adds new ones. The 400 list included more than 1,200 persons during its first 25 years.

In other words, the ranking underscores that capitalism is meritocratic and dynamic. Even those who inherit wealth need skill and judgment to keep — and expand — it. That point hung in the air as Steve Forbes talked Tuesday night about the future. Journalism, after all, is in the midst of epic changes. Forbes embraced the internet early, setting up, in Forbes.com, a separate journalistic powerhouse in its own right.

It did turn profitable, Steve Forbes said, and was eventually combined with the print operation. That precipitated what Mr. Forbes called a “cultural bloodbath.” Forbes wouldn’t be alone in that. In 2014, a majority interest in Forbes was acquired by Hong Kong investors through Integrated Whale Media. Our guess is that there had to be some white knuckle moments for Steve Forbes and his family.

Yet Mr. Forbes was full of optimism, for his company, his country, and his principles. Mr. Buffett predicted at the event that the coming century would see the Dow Jones Average cross a million. Mr. Forbes himself bet that a century hence “people will be infinitely richer with an unimaginably higher standard of living” than today. He reckoned that Forbes, “if guided by the spirit of its founder,” would be there to celebrate it. The United Nations should be so lucky.