As a student at Princeton University 70 years ago, I had drinks with Albert Einstein at his home on Mercer Street. I don’t recall what he had to drink, but I remember him sitting in a reclining chair smoking a long, thin pipe. And none of that is relative to what occurred that evening.

In the spring of 1947, Florida’s liberal senator Claude Pepper came to Princeton and spoke to an overflow audience in McCosh Hall. He was the guest of an organization of students and faculty that I had helped found a year earlier to try to expunge the university’s long-held discriminatory policy of racial quotas for Jewish students, a policy that also excluded blacks from admission.

As I looked out over the packed house as Sen. Pepper and I walked onto the stage a few minutes before 6 p.m., my eyes were drawn to a man in the center of the third or fourth row. He had white hair, was dressed in a threadbare sweater and, as I later discovered, wore sneakers without socks. My eyes had not deceived me; Albert Einstein’s familiar attire could not be missed. Before introducing the senator, I told him that Einstein was in the audience and where he was sitting. As he began his remarks, Pepper announced to the full house that it was one of the proudest moments of his life “to acknowledge the presence of the greatest scientific thinker of our time, Dr. Albert Einstein.” The renowned physicist, 68 years old at the time, received a prolonged standing ovation.

A rush of students surrounded Sen. Pepper after he finished his talk. Standing alone to the right of the stage, I noticed Einstein half-waving at me from his seat. Then he got up, walked to the front of the stage and reached up to shake my hand. In heavily accented but good English, he asked, “Would you and the senator like to come down to the house for a drink?”

I was flummoxed by the invitation, but I must have thanked him because he smiled and suggested we arrive around 8 o’clock. Then he shook my hand again and walked slowly out of the hall. The senator was delighted with the prospect of visiting Einstein in his home, which was near the Institute for Advanced Study, a theoretical research center close to, but not part of, Princeton.

We were greeted by Einstein’s secretary, Helen Dukas, who led us to a comfortable, book-lined sitting room. Seated in his chair (and now wearing slippers), Einstein received us warmly as he smoked his pipe and congratulated the senator for his excellent talk. Pepper returned the compliment, noting in particular the Nobel Prize winner’s scientific contribution to bringing the war with Japan to an abrupt end.

Einstein did not respond. Pepper broke the silence by telling him the letter Einstein wrote to President Roosevelt in 1939 urging immediate research to develop an atom bomb changed the outcome of the war. There was another moment of silence before Einstein spoke. I can still hear that heavy accent as he emphasized that his decision to write the letter “was political, not scientific.” He had long been a pacifist, he explained, and agreed to sign it because his close friend, the eminent scientist Leo Szilard, convinced him the Germans were well ahead in their work on building their own bomb. Although Einstein faced a personal and moral dilemma, he said, the need to stop the Germans dictated the only rational choice.

We spent two hours talking about politics and public affairs — that is, Pepper and Einstein talked. For the most part I listened, which for a 23-year-old seemed the sensible thing to do.

Einstein was eager to point out that while he had approved of our use of the atom bomb as a military necessity against the Japanese, he remained committed to the pacifist principles of nonviolence. He believed strongly in world government. Nonviolence, however, would never have succeeded in stopping Hitler’s war machine, he said. He called Hitler an “insane political gangster” and — without employing the term “collective guilt” — laid the blame for Hitler’s crimes on the entire German population (except for those who had been in concentration camps) for supporting him to the very end with their silence.

Pepper asked Einstein a number of questions about his life as the world’s most prominent scientist. I do not remember a lot of this conversation, perhaps because Einstein’s comments were mostly short, often one-word replies. At one point, however, he made a brief observation that left a deep impression and struck me as remarkable. He said that in his own work over the years he repeatedly found that “90 percent of the time I was wrong.”

Einstein had something more to say about Pepper’s talk. He began by stating his agreement with the senator’s critical remarks about Winston Churchill’s recent “Iron Curtain” speech on March 5, 1946, which both men regarded as leading to heightened tension and a dangerous armament race. While Einstein opposed the brutal and cruel behavior of Stalin — “I would not want to live under such a system of government” — he did not believe the Russians were a threat to peace. He feared far more, he said, those in our country who talked of “preventive war” against the Soviet Union. He could not understand — and Pepper agreed — why Americans were so quick to believe the worst about the Russians.

I changed the subject with a question we had debated a year earlier in a humanities course. I asked Einstein if he thought the world would be a better or worse place without religion. He asserted he was speaking as a scientist, which is why, he said, he did not believe there was an omnipotent personal God “whom I can ask to fulfill my wishes and wants or give help and guidance in human affairs.” He stressed again his commitment to rational knowledge sought through reason and science. This is why he saw no need for religion and science to be in conflict with each other. He had often claimed, he said, that if there was something in him that could be called religious, it was the unbounded joy and amazement at the structure, beauty and grandeur of the world as far as our science could reveal it.

Pepper asked him if he was optimistic about the future in the new atomic era. Again Einstein took a long time before answering. As a scientist, he finally said, he admitted that sometimes he had second thoughts about the wisdom of our using atomic weapons over Hiroshima and Nagasaki. Would their destructive power generate a worldwide distrust of science and scientists in this dangerous age of atomic energy that they had helped create? He reiterated his belief that the elimination of national sovereignty (his advocacy of world government) was imperative if we were to avoid the catastrophe of mass destruction.

Dukas said a few words to Einstein in German, perhaps telling him it was 10 o’clock. Sen. Pepper and I knew it was time to go. Remaining in his chair, Einstein shook our hands and expressed his delight at meeting both of us, and thanked the senator again for his talk. Pepper replied that it was a privilege to have met him, and our good fortune that he left Nazi Germany when he did and came to the United States.

Einstein had a hint of a smile when he said, “I think Hitler was anti-Semitic.”

JOHN H. BUNZEL is an emeritus Stanford professor of political science, a past president of San Jose State University and a former member of the U.S. Commission on Civil Rights.