Tell someone that St. Paul is home to the metro’s finest Art Deco buildings, and you might get a condescending look.

Not because it’s St. Paul. Because the buildings are really Moderne.

The terms are interchangeable for some, but they’re different styles. Art Deco is ornate, floral, often fussy; Moderne is angular, stripped down, romantically futuristic.

The former was the final style of the Jazz Age, the spume from the last bottle of champagne; the latter was the clear-eyed work of forward thinkers eager to build cities in a style that kicked history into the dustbin.

Some of the greatest skyscrapers of New York are Moderne, with Deco touches; they all came at the end of the boom, the steam-shovels excavating as the bread lines lengthened.

Minneapolis has a modest bequest of Moderne buildings, such as the Post Office. St. Paul has a group of buildings that made it, for a while, the region’s epicenter for futuristic towers. Let’s start with the biggest, and most sedate.

First National Bank (1931)

It was designed by Graham, Anderson, Probst and White, a huge Chicago firm whose sober corporate headquarters looked as if they’d been whittled from enormous cliffs of gray stone. For decades the tallest building downtown, it seemed to turn its back on its city. The entrance is on the side, but its two wings and tall tower — topped with the big red 1 — face the river. The side facing downtown is mostly blank, sending a peculiar message: There’s nothing downtown worth a window. Most buildings don’t have a backside. This one does.

Buildings of this era often had interior spaces glittering with nickel, ornamented with Deco designs custom-made for the site — an explosion of detail that contrasted with the poker-faced exterior. Not so the First National Bank; the main public area was the banking floor on the second and third levels — an austere hall that dwarfed the patron and must have cost a fortune to heat. Ungainly chandeliers, square fluted columns. Don’t ask to see it. All gone.

At least the main floor looks the same as it did on opening day. The elevators have strange designs that look like a 1930s pulp-mag ad for a mystic amulet that will bring you luck. Along the ceiling runs a triangular motif, each little pyramid containing a rising sun. Pillar after pillar sheathed with veiny marble in two earthy hues. It’s a public space that should have lots of people heading to and fro, stopping for a shine, paging through the latest issue of Liberty at the magazine stand.

Main U.S. Post Office (1934)

Minneapolis’ Moderne post office is modest compared with the St. Paul brute on Kellogg. Designed by Holabird and Root, Chicago architects who defined the Moderne style, it answers the question, “What’s the exact opposite of a Rococo cathedral?” Some Buck Rogers metal adorns the windows on the bottom floors, but that’s about all you’ll get for exterior decoration. If it were covered with black glass it would be just another dull 1960s office tower, but at the time this was like a building from an alternate-universe United States where the Crash of ’29 never happened, and a powerful technocratic society was inventing TV and airships and robots and radium serums to treat disease.

But no; just a post office. But yes, a reminder that the government was still building things, even if no one else was. It’s being rehabbed for housing now, and while the occupants will not be obligated to furnish their homes to look like the drawing rooms of the Hindenburg zeppelin, it wouldn’t be a bad idea.

City Hall (1932)

It’s famous for one of the unique public spaces in either city — the War Memorial Concourse. Black stone, copper trim, the enormous white onyx statue of the Vision of Peace on one end, making visitors wonder if St. Paul was settled by Mayans. It’s an impressive space, and you can’t quite figure out why it’s not also a depressing space. A narrow well lined in black ought to make you think that the Wizard of Oz’s evil twin waits at the other end.

Just a few yards beyond is the elevator court — butter-colored stone with brash metal elevator doors, embossed with allegorical St. Paul symbols. The mailbox has a stylized eagle to denote the “sacred federal duties” of the U.S. Postal Service, and as you look at the design, there’s a word that comes to mind. But you push it away, because that’s ridiculous.

The word comes back when you’re outside, admiring the carvings of fierce-eyed Justice and the rest of the pared-down iconography. You look at the lack of curves, the simple massing, the proud square forms that seem to suggest anything other than stern right angles is a sign of decadence. It’s … rather fascist, isn’t it?

Not really. The totalitarian architecture of the ’30s had a horrible deadness. The columns were fingers in a fist. In America, the same style suggested the civic simplicity of a democracy. It was a rational machine for doing the “will of the people,” not an intimidating monument that humbled the individual.

Moderne and Deco don’t have to be either-or; they play together nicely, as the 1937 Tri-State Phone Company’s building at 70 W. 4th St. shows. It has the same marble and stone hues as the Northwestern Bell building in Minneapolis, but its tidy dimensions and upper-floor ornamental flourishes make it much more playful. The Market Street entrance has some pure Deco touches, with a stylized fountain motif that looks like it could have been lifted from a 1928 Parisian fashion mag.

The Northern States Power building at 360 Wabasha — now part of the Ecolab complex — is a truncated version of the larger tower they intended to build, but you don’t miss the unbuilt floors. Over the door is a bas-relief of allegorical figures representing the virtues and benefits of electricity. It’s a mythical counterpoint to the everyday reality shown on the carvings over City Hall’s entrance, where cops and pedestrians and shoppers and children are walking along a downtown street.

The Wabasha figures still look futuristic after all these decades; they still point to a path down which we only made a few steps before Depression and war rewrote the maps. Looking at these buildings you can sense optimism and confidence, declared at a time when neither seemed a wise bet.

The Moderne style also worked well at the modest level. The Women’s City Club building at 305 St. Peter Sreet, the sort of building invariably described as a “jewel box,” has a delicacy and simplicity that achieves a marvelous sense of elegant sophistication with almost no details at all.

By the time we climbed out of our troubles, the style was old. Futurism dates poorly; nothing is as old as yesterday’s idea of tomorrow. These buildings have worn well because they do two things a building must: They demand respect — and they earn it.