This is hidden brain.
I'm Shankar Vedantam.
Barely a week after assuming office, President Donald Trump set off a worldwide firestorm when he decided to temporarily ban migrants from seven muslim majority countries and refugees from all over the world from entering the United States.
I'm establishing new vetting measures to keep radical islamic terrorists out of the United States of America.
We don't want them here.
We only want to admit those into our country who will support our country and love deeply our people.
Trump's executive order was greeted with support in some quarters.
President Trump came in here not just as a commander in chief for the military.
He's a CEO, and he's trying to run.
He's trying to protect everybody in the country, and he's trying to keep everybody, all Americans, regardless of religion, safe from the potential terrorists that come in.
I mean, some people from some of these parts of the world believe, believe it or not, want to kill us.
And with dismay and outrage in others, spontaneous protests erupted at airports and public squares across the nation.
You've got an obligation and a duty.
To do what?
Resist, resist, resist, resist.
One technique we often use to understand current events is to look to the past to see what history can teach us.
But this is a process that is fraught with psychological peril.
We're often inclined to draw lessons from history that suit our preconceived notions of how to think about the present.
Historians say there are important lessons that we can draw from the past, but there are also dangers to overly neat analogies.
One analogy that many people have reached for in recent days is the story of the SS St.