Unlimited Expansion?

I just finished reading the ex-British spy John Le Carre’s latest book, Agent Running in the Field. I can’t forget something he said once: “If we go on believing that there is unlimited expansion in a limited globe, I think we are heading for destruction. The globe will survive but mankind won’t.” I couldn’t help but be reminded of my Scandinavian history when farms passed in the family to the oldest son. What options did the younger sons have? Maybe emigrating to the U. S. where the promise of free land drew some, but our land has filled up and is not free anymore. People are still on the move around this globe because of famine, drought, political unrest, invasion from neighbors, et cetera. Unfortunately, resources are limited, and in many cases nonexistent. The myths and legends of the Vikings say they sailed away in their long boats and seized what they wanted.