Secretary of State George P. Shultz will deliver an address entitled "Progress, Freedom and Responsibility" this morning when thousands gather in Tercentenary Theater for the second of three convocations marking Harvard's 350th anniversary.

The theme of today's event is the University in a changing world.

The secretary of state agreed to offer the keynote address five weeks ago, after President Reagan, Japanese Prime Minister Yasuhiro Nakasone, Indian Prime Minister Rajiv Gandhi, and Philippine President Corazon C. Aquino had declined Harvard's invitation.

When the White House, citing the president's busy schedule, announced in March that he would not attend today's convocation, it unsettled plans Harvard administrators had set years in advance.

Reagan is currently vacationing on his mountaintop ranch in Southern California. (See related story, page 7.)

Shultz's address will follow speeches by Cambridge Mayor Walter J. Sullivan, Massachusetts Gov. Michael S. Dukakis, and Speaker of the House Thomas P. "Tip" O'Neill Jr., Harvard's Congressman.

They are expected to talk about how Harvard affects and is affected by its city, its state, its country, and the world.

Dean of the Faculty of Arts and Sciences A. Michael Spence will respond to the public officials' speeches, Jeffrey Rosen '86 will deliver a short undergraduate oration, and Boylston Professor of Rhetoric and Oratory Seamus Heaney, the noted poet, will read a poem he composed for the anniversary celebration.

The expected crowd of approximately 18,000 will then hear recorded excerpts of memorable speeches delivered at Harvard since the tercentenary celebration in 1936.

The excerpts include remarks by Winston Churchill, Franklin Delano Roosevelt '04, and George C. Marshall, the secretary of state who made history here when he announced America's plan to rebuild post-war Europe.

Spokesmen for the State Department did not comment on Shultz's speech, but they said the text was still being revised last night.

Shultz has been vacationing at his farm in western Massachusetts. He will arrive in Cambridge by motorcade tomorrow morning in time for a 15-minute meeting with Jamaican Prime Minister Edward Seaga '52 before the convocation, an aide said.

Harvard originally intended to honor Shultz at a gala dinner that was scheduled to take place last night in Memorial Hall. But Shultz was not able to attend, and a divestment protest caused administrators to cancel the dinner.

Shultz has been on vacation since making two stops in Central America on August 15 and 16.

After today's convocation Shultz and his wife will join President Derek C. Bok and his wife, Professor Sissela Bok, at a luncheon honoring the secretary of state in the Fogg Art Museum.

After a meal that is to include cream of carrot soup, cold filet of sole, fruit compote, and champagne toasts, Shultz will return to his farm, an aide said.