The pattern of human population growth in the 20th century was more bacterial than primate. When Homo sapiens passed the six billion mark we had already exceeded by perhaps as much as 100 times the biomass of any large animal species that had ever existed on the land. We and the rest of life cannot afford another 100 years like that.

Will we solve the crises of next hundred years? asked Krulwich. “Yes, if we are honest and smart,” said Wilson. “The real problem of humanity is the following: we have paleolithic emotions; medieval institutions; and god-like technology. And it is terrifically dangerous, and it is now approaching a point of crisis overall.” Until we understand ourselves, concluded the Pulitzer-prize winning author of On Human Nature, “until we answer those huge questions of philosophy that the philosophers abandoned a couple of generations ago—Where do we come from? Who are we? Where are we going?—rationally,” we’re on very thin ground.