In a recent post, I praised the 19th-century journalist and essayist Walter Bagehot for his subtle mind and intellectual honesty. These qualities stand out because among the most difficult challenges in politics is not allowing truthful inquiry to become subordinate to one’s allegiance to a political cause, a political party, or a political ideology. It’s harder than we think, and rarer than we would wish, to find individuals who are open to a new set of facts, especially when they run counter to settled ways of thinking.

I thought about all this while recently watching an American Experience documentary on the life of Ronald Reagan. It covered a lot of ground, of course, but in the context of this discussion, one thing stood out: Reagan’s willingness to adjust his thinking in light of new circumstances. What I have in mind is Reagan’s attitude toward the Soviet Union.

Ronald Reagan is rightly considered one of the West’s most vocal and courageous critics of Soviet communism. Hatred for totalitarianism was, his biographer Edmund Morris said, among the very few hatreds Reagan ever held. In 1983, in a speech before the National Association of Evangelicals, Reagan referred to the U.S.S.R. as an “evil empire.” Such blunt language from an American president, even though true, caused outrage among the political class. Reagan, it was said, was a saber-rattler, needlessly provocative, reckless and even war-like. The vilification came in waves. But Reagan didn’t much care. He spoke the truth as it was — and in doing so, he inspired dissidents across the globe and re-moralized American foreign policy.

Fast-forward to May 1988, when Reagan toured the Soviet Union after having participated in several summits with General Secretary Mikhail Gorbachev. When asked whether the Soviet Union was still an “evil empire,” Reagan said no, it wasn’t. “I was talking about another time,” Reagan said, “another era.” And he was quite right.

President Reagan knew that the Soviet Union was hardly a model democracy. In fact, he made a point of meeting with more than 100 dissidents during his trip. The New York Times reported at the time, “In a reflection of the Kremlin’s irritation with President Reagan’s plans to dramatize human-rights issues during his visit to Moscow, a senior Soviet official said … that a planned Presidential meeting with Soviet dissidents would be an unwelcome breach of superpower protocol… Mr. Reagan’s determination to press the human-rights issue in Moscow loomed as a potentially disruptive issue on the eve of his arrival. Moscow has traditionally resented what is seen here as an unwarranted and intrusive American assumption of moral superiority.”

Still, the circumstances in 1988 were profoundly different than they were in 1983. Mr. Gorbachev was a Soviet leader — the first Soviet leader — Reagan (and Margaret Thatcher) could do business with. Reagan eventually signed sweeping arms control treaties that went far beyond anything the Nuclear Freeze Movement had ever called for.

It’s worth noting that Reagan, who had been a reviled figure by the left, was excoriated by some conservatives for going soft on the Soviet Union. He was accused of being a “useful idiot for Soviet propaganda,” for losing his way and succumbing to the chimera of arms control agreements. (It should be said that the criticisms of Reagan from conservatives was not nearly as widespread as it was from liberals.)

But what we saw in Reagan was quite a rare thing among politicians — a man of deeply held convictions who even while maintaining those convictions was willing to adjust his thinking in light of new developments. He was able to perceive the core realities of his time and align his views and policies to them. And so one of the most principled and ideological presidents in American history also turned out to be among its most flexible.

During his presidency, Reagan’s critics said he was simple, shallow, and unreasonably stubborn. In fact, he was a person of impressive depth, a man of many parts, and reasonably stubborn. It simply took some people a bit longer than others to understand that.