Bill Gates vs. Matt Ridley

This is an interesting "debate" between Bill Gates of the Gates Foundation (and if you're from another planet, Microsoft) and Matt Ridley, the Rational Optimist, of whom I've posted before. The debate is a well-argued one, with each participant respecting the virtues of the other. Gates, like me, admires Ridley's work on history and his guiding metaphor of exchange--exchange of stuff and ideas--as a prime mover in human improvement. I agree with Gates, however, that Ridley sometimes seems to take an Alfred E. Newman (my choice, not Gates's) attitude ("What? Me worry?"). Gates rates risks with available knowledge, understanding that innovation could change the scene, but we can't count on it. I agree. In all, this is an intelligent exchange between two very capable and, I might add, well-mannered gentlemen.