The new San Jose City and San Jose State University library is on the corner of San Fernando and 4th streets in downtown San Jose. It is eight floors tall and occupies the northwest corner of the campus.

A wonderful gift in a bad package -- that's what the new library presents San Jose.

A new downtown library can be a tremendous urban asset -- a major building that nurtures the curiosity of children and the wisdom of adults. But the Dr. Martin Luther King Jr. Library falls short of the architecture downtown San Jose has come to expect. Even more disappointing, it doesn't rise to the quality of other big public libraries around the country.

The design by Gunnar Birkerts Architects and Carrier Johnson (in association with Anderson Brulé Architects) resolves many of the thorny issues between public access and scholarly study. And inside it has one good idea: It fills every floor with natural light, well-modulated for individual study carrels and large reading rooms. But the other essentials of great public architecture were never fleshed out, leaving us with our most awkward big building built in downtown San Jose since the 1970s.

This building -- a pivotal connection between downtown and the university campus -- should have been a splendid gateway. But its exterior massing is ungainly and uncontrolled. Its detailing is half-baked and aimless, austere and unwelcoming.

This key site and this library's daring mixed use should have inspired magnificent urban architecture.

The new main library in Phoenix, designed by architect Will Bruder (who once worked with Gunnar Birkerts), is an inspired example. The design unites past and high-tech future. It is a high-tech tent, a vast space covered by a sky-lit ceiling propped on Space Age tent poles. Graceful screens filter the strong desert sunlight to create a shady cavern with the feel of a cool grotto. Outside, its deep red rusted walls look ruggedly geologic, perfectly suited to the desert, sculpted in a series of memorable shapes.

There is no such magic in our library's long interior ``main street,'' which connects the busy corner of Fourth and San Fernando with the quiet green campus quad. There's a large atrium at the center, ringed with balconies looking down from the upper floors, and populated with the checkout desk, escalators, elevators and artwork. It will efficiently draw people and help blend city and campus users. But it is also a bombastic and boring space. It seems to have learned nothing from the shortcomings of Modernism since the 1960s.

We see all the cliches: the large-scale, three-dimensional structural framework of the building is exposed to view, an unimaginative nod to Modern rhetoric about structural honesty. The space is impressively large, with little sense of place. There is no human scale in the tall balconies (14 feet, six inches from floor to floor, even taller on the ground floor).

The manipulation of light is one element that is done well. High over the atrium, a slanting glass roof lets light filter into the interior. Ground-floor wells let natural light even into the basement. The top-floor reading room, paneled with warm wood, is a lofty space with balanced light from high windows and superb views of the city -- the best available in a public building.

The other well-done part of the design is the smallest and most human: the individual desks, or study carrels. Especially when they hug the outer wall, these blend symbiotically with the building; windows are lowered to the eye level of a seated person, and individual canopies provide balanced light and privacy.

But as an urban building, too big to ignore, too important to excuse, the library fails. It is divided into two distinct pieces -- a low four-story base, and an eight-story tower cranked at an angle. The design attempts some urban gestures, but they are cursory, halfhearted and unresolved.

The scale is too large, and the detailing of the windows is too severe. The obligatory glassy modern curtain wall at the sidewalk opens up the cafe and the children's room to public view but it is also confusing -- neither a clear gateway to welcome citizens nor a smooth sequence from outdoors to indoors.

Visually it is a dull building.

Stand across San Fernando in front of the new Century Commons housing project and look back at the library. All of the building's planes are essentially the same size -- the slab sides of the tower, the slab facades of the base. The composition has no contrast, no interplay to give the building life. Then turn to the left and note how the new Fourth and San Fernando garage composes its facade with thin horizontals and sturdy verticals, flat planes and textured planes, in a varied and lively urban design. That's how it should be done.

The good news is that this muddled design is not setting the architectural course for buildings at SJSU. The new housing complex under construction at Tenth and San Salvador streets and the new art museum are both radically better designs. The bad news is that this library is designed to absorb growth for 20 years, so it will be around for a long time.