Before a reader reaches a book inside Geisel Library, eight glass panels ask for four verbs: READ, WRITE, THINK, DREAM. John Baldessari's entrance installation has been giving those instructions for 25 years, long enough for the UC San Diego students pictured on the doors to return as parents, professionals and, in one case, a memory carried by family.

Baldessari began considering the commission in 1994. The Renaissance bronze doors of the Baptistery in Florence offered a historical starting point, but he replaced religious narrative with questions about what a university entrance could hold. Geisel's main doors were among the most crossed thresholds on campus, a place where art would be handled by the daily movement of study rather than approached as a separate destination.

The work, unveiled in July 2001, places photographs of UC San Diego students above shelves of books selected with library staff. Each ten-foot panel belongs to the same composition but keeps an individual face. Primary colors run across the glass, while images of a monitor and television occupy the corners. The four words are both commands and a compact description of the labor happening beyond them.

Time has supplied a second layer. Ernesto Martinez, class of 2003, returned this summer with his family and found the younger version of himself still embedded in the entrance. He grew up in Imperial County; his grandfather came through the Bracero program, and his father worked as a migrant farm laborer. Martinez studied economics and ethnic studies, later earned a Harvard doctorate in cultural anthropology and now works as a market-research strategist.

Denise Pacheco, also class of 2003, chose to be photographed in a Zapatista shirt. She went on to graduate study at UCLA and now leads alumni diversity programs there. Her clothing on the panel records a political and cultural identification that a conventional donor portrait might smooth away. The installation keeps it at the point where thousands of students enter an institution built to classify knowledge.

Another panel holds Mikéah Jennings, who became a performer and teacher. Jennings died at 43, and family members have returned to the doors. That visit changes the meaning of a student photograph without changing a piece of glass. A work designed around youth and possibility now also contains grief, continuity and the evidence of a life that extended beyond campus.

The Stuart Collection places art throughout UC San Diego rather than confining it to a museum. Baldessari's doors make that approach unusually literal: the object is architecture, artwork and route. Students may pass through without stopping, catch one word in reflection or recognize a face only after learning the story attached to it. Participation ranges from deliberate viewing to the simple act of opening the library.

Anniversaries can flatten public art into a date and a familiar photograph. These doors resist that treatment because their subjects kept living. Their degrees led into research, education, business and family histories; one life ended while the image remained in common view. After a quarter-century, READ/WRITE/THINK/DREAM is not frozen at its unveiling. It is an entrance where the campus keeps crossing paths with the people it once pictured becoming.