Flanked by fervent demonstrations at the start of Egypt's recent revolution, the Bibliotheca Alexandrina was guarded by the linked arms of Egyptian youth protecting what they believed to be a national treasure of science and art.

"They saw the library for what it was...and the crowds responded," recalled its director Ismail Serageldin in a video address to the 2012 American Association for the Advancement of Science (AAAS) Annual Meeting. "Not a stone was thrown at the library."

To Serageldin, the Bibliotheca Alexandrina and the values of science that it promotes will be more essential than ever as Egypt struggles toward new government and a new global engagement.

Science, he suggested, operates on principles like tolerance and rationality that lead naturally to a "better and more humane society."

The best "defense against extremists is not by censorship or autocracy," he said." It is by embracing pluralism, and defeating ideas with ideas, and here science has much to say."

Serageldin said the library has always provided a home for discussions about the future of the Muslim world, and a place where scientists, artists and religious and political leaders can work together to build a civil society.

For religious leaders in the region who advocate a return to Islamic practice from centuries ago, Serageldin said, the library can remind them that "there is a great Muslim and Arabic tradition of science and tolerance."

The rational approach of historical scholars like Ibn al-Nafis, an Arab physician who described the circulation of the blood during Europe's Dark Ages, "is the tradition that must be revived if the Arab world, Muslim and non-Muslim alike are to rejoin the ranks of the advanced societies of our time," he said.

Serageldin has been an advocate for science in the developing world for more than three decades. An accomplished researcher in biotechnology, sustainable agriculture, and rural development, he has worked at the World Bank and was a chair and member of TWAS, the Academy of Sciences for the Developing World.

Speaking like a proud parent, Serageldin took the plenary audience on a virtual tour of the Bibliotheca Alexandrina's multiple institutions, galleries, and research in everything from robotics to Hellenic art. The library is built very near the site of the original Library of Alexandria, a wonder of the ancient world which disappeared entirely more than 1600 years ago.

Especially important, Serageldin said, are the library's community activities like science fairs for children and its science museum. The events often focus on the contributions of Arab and specifically Egyptian scientists, he said, to emphasize to children "that 50 centuries of science stands behind you as you young Egyptians try to make your own contributions."

In some respects, the library's mission follows Serageldin's "Seven Pillars of the Knowledge Revolution" vision, in which the global knowledge community is mobile, digital, and interconnected across disciplines and national borders.

Serageldin said it was a "magic, exulting moment" when the young Egyptians protected the library during the January 2011 demonstrations. Although the protests sometimes have turned more violent and political turmoil has challenged the progress of the revolution, he believes that the library will remain a beacon of rationality and inspiration for Egypt and the world.

"My youthful colleagues and I," he said, "committed to the values of science and armed with a revolutionary ardor, join hands with you as the builders of the global knowledge society of tomorrow."