Justin Gregg is an animal cognition expert -- he studies what goes on inside the heads of other creatures, and what that means for us. He’s a captivating science writer: one of his specialties is explaining whether dolphins are actually smart, and his most recent book is “If Nietzsche Were a Narwhal.” In an expansive conversation, Justin and Adam discuss what makes the human mind unique, muse over the life lessons we might learn from the animal world, and debate whether or not, when it comes to consciousness, ignorance is really bliss. Transcripts for ReThinking are available at go.ted.com/RWAGscripts