It seems to be a human failing to think that trying times call for a redoubling of purity of principle. We see it time and again in history: the trial of Socrates after the Athenian defeat in the Peloponnesian War, the Inquisition in response to the Protestant Reformation, the Self-strengthening Movement in the faltering Qing Dynasty China, the Cultural Revolution in the same country decades later, the list can go on ad infinitum.

And here and now in America, amidst the deepening political crisis, we hear calls to fundamentalist purity from the left.

It has never worked, throughout history, and it won’t now.

Let’s say you’ve got squirrels in the attic. They got there because your house has needed major renovations for quite a while, but you got by with stop-gap measures, because the renovations would involve temporarily opening up the house to the outdoors, and you have to live there while the work is going on.

Now you discover skunks have moved in under your deck.

Do you think it’s sensible to choose this moment to drop everything and start gutting the house?