The concerns that influence passions, the issues that inflame them, each generation must choose for itself.

As the hour of the noon rally approached, I stood among the cheering, clapping students gathered at the University of California campus here. Thousands of others joined those who were staging the sit-in so the crowd overflowed onto the plaza, lawn and streets. The day before, police had arrested 159 protesters, and in response, thousands of Cal students boycotted classes.

Having seen today's college students seem guided more by paycheck and career concerns than social and political consciousness, it was a refreshing sight to see students who had found a cause worthy of their passions.

"This is one of the ones I would demonstrate for," said a young brown-haired woman at the rally. "It upsets me that I am here in the U.C. system." And all around her chants filled the air: "U.C.! U.S.A.! Out of South Africa! U.C.! U.S.A.! Out of South Africa!"

The cause of this unrest is the university's $1.8 billion investment in corporations and banks doing business in South Africa. Because the protesters believe these investments "contribute to the enslavement of black South Africans under the apartheid system," they are demanding that the U.C. board of regents divest itself of these stocks.

But the students' fervor is not simply to be spent in rallies, boycotts or even arrests. They have set a deadline on their demand for divestment. They want the $1.8 billion in stock out of South Africa by May 16 -- but it is not clear how they intend to enforce the deadline.

Cal students at Santa Cruz are calling the library the Nelson Mandela Library for the jailed South African freedom fighter. Berkeley students unofficially renamed Sproul Hall in honor of Steven Biko, another South African civil rights leader, who died in police custody in 1977.

Moreover, many of the arrested students identified themselves as Steven Biko, or in the case of women, as "Stephanie Biko." Twenty-nine of the protesters spent extra time in jail for refusing to accurately identify themselves.

While it took the human rights scandal of South Africa's policies to ignite this fire, protests have well-known antecedents on the Berkeley campus. Twenty years ago, Berkeley was practically synonymous with social and cultural movements: the free speech movement, the civil rights movement and the anti-Vietnam War movement spawned riots in People's Park, prompted gunshots on Telegraph Avenue and brought the sting of tear gas to the eyes of protesters.

One professor, a living link between the two eras, rose to declare that the currently aroused political consciousness among Berkeley students is more significant than that of two decades ago.

"The difference between now and the '60s when I was a student is dramatic," said Prof. Kenneth Simmons of the School of Architecture. "This protest is a thousand times more significant because of the current conservative political atmosphere in this country out of which it emerges."

Another speaker, clad in a denim outfit like the de rigueur attire of the '60s, said the presence of so many blacks among the protesters was another major difference between the earlier period and the present.

But the Berkeley outcry also demonstrates another characteristic of the apartheid protesters whose numbers are increasing across the country. The men and women who have stood up to denounce the denial of basic political rights to the black South African defy easy categorization. At Berkeley the protesters included Asians, Caucasians, blacks and Hispanics. Numerous persons in wheelchairs wore the red ribbon of support.

And they came in all manner of clothing: jeans and shorts, the rumpled professor look, buckskins, dreadlocks and Madonna lookalikes. But beneath the varied exterior there was clearly a similarity of purpose and of passion. Standing under the hot sun as the students' chant rose dramatically, one of another generation could glimpse a certain beauty in their zeal.

Though the men and women in South Africa might never witness the heat of the Berkeley students' intensity, such passion is the stuff of which freedom ultimately is fashioned.