The classic opening scene of 2001, A Space Odyssey shows an ape-man wreaking havoc with humanity's first invention--a bone used as a weapon to kill a rival. It's an image that fits well with popular notions of our species as inherently violent, with the idea that humans are--and always have been--warlike by nature. But as Douglas P. Fry convincingly argues in Beyond War , the facts show that our ancient ancestors were not innately warlike--and neither are we.