Albert Einstein, the German-born Nobel prize-winning physicist, became an outspoken civil rights advocate after immigrating to the United States in the 1930s to escape the Nazis. But newly published travel diaries from the 1920s, when Einstein and his wife Elsa embarked on a months-long voyage to the Far East and Middle East, reveal a younger man who himself harbored xenophobic and even racist views.

In passages from The Travel Diaries of Albert Einstein, edited by Ze’ev Rosenkrantz, Einstein muses on the character and nature of the people he meets in Singapore, Hong Kong, China, Japan and Palestine, sometimes in insulting and stereotypical terms.

The Chinese, Einstein wrote, were “industrious” but also “filthy.” He described them as a “peculiar, herd-like nation often more like automatons than people.” Even though he only spent a few days in China, Einstein felt confident enough to cast judgment on the entire country and its inhabitants, at least in his private journal.

“It would be a pity if these Chinese supplant all other races,” Einstein wrote. “For the likes of us the mere thought is unspeakably dreary.”

While visiting Ceylon, modern-day Sri Lanka, Einstein was moved to pity for the crowds of beggars lining the streets of the capital city Colombo, but also described the mostly Indian panhandlers in dehumanizing terms. “They live in great filth and considerable stench down on the ground, do little, and need little,” he wrote.

Later in life, Einstein compared of his experience as a Jew in Germany—where anti-Semitism dogged him long before the rise of Hitler and the Nazis—to the plight of blacks in America. As early as 1931, Einstein spoke out against the racially motivated “Scotsboro Boys” trial and contributed as essay on racism to a magazine published by W.E.B. Du Bois, co-founder of the NAACP. In a famous 1946 commencement address at Lincoln University, a historically black college in Pennsylvania, Einstein said that segregation was “not a disease of colored people. It is a disease of white people. I do not intend to be quiet about it.”

So what is to be made of Einstein’s early, private writings in which the greatest mind of the 20th century expressed such ugly views?

Rosenkrantz, who is senior editor and assistant director of the Einstein Papers Project at the California Institute of Technology, told the Washington Post that “It would be easy to say, yes, he became more enlightened,” but that it’s possible that Einstein continued to harbor racist or xenophobic opinions in private.

What’s clear is that Einstein was a complex human being with faults as well as tremendous gifts.

“One should emphasize the different elements and contradictory elements in the statements that he made and in his personality,” Rosenkranz told the Post. “On one hand, he was very generous and very favorable. … But there’s also these statements that one should not ignore.”