As if social media couldn't get any dumber, astronaut Scott Kelly felt the need to apologize after he was attacked by an online mob for using a rather innocuous quote from Winston Churchill.

"Did not mean to offend by quoting Churchill," Kelly wrote. "My apologies. I will go and educate myself further on his atrocities, racist views which I do not support. My point was we need to come together as one nation. We are all Americans. That should transcend partisan politics."

The episode provides us an opportunity to revisit the controversy about the celebration of historical figures in modern times.

Churchill had a long and storied political career. He could be boorish and stubborn, with a tendency to see things in black and white terms, and there were times when he got things tremendously wrong – for instance, his colonialist tendencies polluted his opinions on India.

But many of the attributes that frustrated critics also contributed to his heroic leadership during World War II that saved Europe – and arguably the rest of the world – from Nazi dominance. He was an early and fierce critic of Adolf Hitler when most people of his social status believed the Nazi leader was a harmless or even positive force in Germany. In 1940, when the most reasonable course seemed to be to cut a deal with Hitler, he chose instead to fight on, rallied the public, and helped bog down Hitler until the Americans arrived.

On top of that, he was a tremendous orator with one of the sharpest wits of any figure in political history.

If Churchill becomes off limits, then you're going to have to stop quoting a lot of historical figures.

Why shouldn't liberals refrain from quoting FDR, given the internment of the Japanese and the fact that he ignored Jews aboard the SS St. Louis, sending hundreds back to their deaths? Heck, most presidents would have to be considered racist or sexist by today's standards – let alone our Founding Fathers, who actually owned slaves.

But we won't be able to stop there.

One of my favorite authors, Charles Dickens, was responsible for creating one of the most anti-Semitic characters in English literature – the awful "Oliver Twist" villain Fagin, who effectively enslaves children in a pickpocket ring and greedily clutches his stolen possessions. As if there were any doubt about his background, Dickens simply refers to Fagin as "the Jew" dozens of times and the character has routinely been depicted in illustrations and films with a long hook nose. Should we now refrain from reading or quoting Dickens?

To be clear, I have actually been quite supportive of protests against Confederate monuments and public flag displays, because in such cases, the act being celebrated was a treasonous rebellion meant to preserve and expand the inhumane institution of slavery. There was no good part of the Confederacy, despite over a century of efforts to obfuscate the truth around claims of honor and a heroic struggle for state sovereignty.

In the case of Churchill, or other historical or literary figures, we aren't celebrating the troubling aspects of their record, we're celebrating the positive ones. We should "never surrender" on this, or else all positive aspects of historical figures will wash away within decades, as attitudes change.