Shad: Lessons from the past have never been more important

Let's take a quick look at the rear view. Shad reflects on a common thread uniting many interviews on this week's show: the enduring importance of revisiting the past. 

Over the past few days we've heard from Nick Offerman on American history, Greg Proops on ancient history, Karina Longworth on movie history and David Suzuki on his personal history. 

So why the impulse to look back? And what can history teach us about the future?