Albert Einstein was one of the greatest humanists of our times. He became famous for revealing how much of our universe works, through the theories of General and Special Relativity. But he used this fame to support and further humanist ideas.
He opposed the ultra-nationalism of the Kaiser Republic during WWI. Einstein considered himself more of a citizen of the world than of a nation-state. He believed in the higher ideals of freedom, liberty and a right to oppose one's own government, even in wartime. Although he is made out as a devout religious believer today, he was attacked during his lifetime for his lack of belief in a god. He was attacked in letters to the editor for not having the religious views of most Americans.
He was criticized for his defense of those hauled before the anti-American Congressional committees that engaged in witchhunts against critics of the far right. He saw in these witchhunts, the echo of the Nazi government persecuting their own critics. The fascist leaning J. Edgar Hoover, the director of the FBI for decades, had Einstein's mail opened, phone monitored and tried to have him connected to Soviet spies.
Dr. Einstein stated that those called to testify before these anti-American Congressional committees should refuse to answer not on 5th Amendment grounds, which would imply that the committee has some legitimate jurisdiction in asking a citizen who has commited no crime, but because it is a violation of their basic Constitutional rights and liberty to be made to answer to government officials about their views.
The Nazis in Germany didn't develop nuclear weapons and one of the major reasons that they did not, was because of the Jewish background of Einstein and other scientists, especially when it came to relativity theory. To them science was to be denied because not to do so, in their opinion, would weaken their anti-semitism.
This is similar to those on the far Christian right who decry evolution because it is against their fundamentalist religious beliefs. To them, the reason not to believe in evolution is not so much the science, but because they don't like the idea that it would be true. Dr. Einstein visited Japan during the intrawar period. A newspaper in that nation decried an "excessive reliance on science and the contempt for faith." Japan of course, being beholden to fascist ideology, as Nazi Germany. Now, science is the only tool to really learn about the workings of the universe and nature. Faith is belief for the sake of belief. Any scientist of any worth will of course utilize science because to believe in something without evidence, shows a contempt legacy for men and women such as Dr. Einstein, let alone to human reason.